Transient overvoltage cooperative suppression control method for AC / DC hybrid power system

Abstract

The invention discloses an AC / DC hybrid power system transient overvoltage cooperative suppression control method, which comprises the steps of determining a transient electromagnetic energy level of a system based on electrical quantity data acquired in real time during a fault period of an AC / DC hybrid power system, the transient electromagnetic energy level is used for quantifying a scalar or function value of excess electromagnetic energy in the alternating-current and direct-current hybrid power system after the fault; in response to the transient electromagnetic energy level exceeding a preset threshold value, taking minimization of the transient electromagnetic energy level as an optimization target, and generating a cooperative control instruction set on line, the cooperative control instruction set comprising a first type of instructions for scheduling reactive power regulation resources and a second type of instructions for scheduling active power regulation resources; and according to a preset sequential logic, executing a cooperative control instruction set to reduce transient electromagnetic energy and suppress transient overvoltage. By introducing reactive and active resource cooperative scheduling based on global transient energy observation, the suppression effect and dynamic stability of the transient overvoltage of the AC / DC hybrid power system are significantly improved.

Description

A method for coordinated suppression and control of transient overvoltage in AC / DC hybrid power systems Technical Field

[0001] This invention relates to the field of power system safety and control technology, and in particular to a method for coordinated suppression and control of transient overvoltage in AC / DC hybrid power systems. Background Technology

[0002] Hybrid AC / DC power systems have become the mainstream form of modern power grid development due to their significant advantages in long-distance, large-capacity power transmission and efficient integration of renewable energy. However, the deep coupling and interaction between the AC and DC subsystems during fault transient processes have also led to more complex stability problems than pure AC systems, with transient overvoltage being particularly prominent. When the system encounters a large disturbance (such as disconnection after an AC short-circuit fault), a large amount of excess reactive power may be generated in a short period of time. In addition, the short-term reactive power support capacity of renewable energy units is reduced due to grid disconnection or control mode switching during the fault, and the rapid reactive power regulation performed by the DC transmission system converter to maintain power transmission, these factors combine to easily cause a sharp rise in voltage at critical nodes of the system. In severe cases, this may lead to a chain of faults such as large-scale grid disconnection of renewable energy and equipment insulation damage, directly threatening the safe and stable operation of the power grid.

[0003] Traditional and existing technologies for suppressing transient overvoltages primarily focus on rapid compensation and balancing of reactive power, such as deploying dynamic reactive power devices like Static Var Compensators (SVCs) and Static Synchronous Compensators (STATCOMs). These methods are essentially "local" or "single-point" passive response control, where control commands are often generated based on the deviation between local voltage measurements and setpoints, lacking a holistic understanding of the system's global transient energy distribution and evolution trends. More critically, existing methods generally treat the AC and DC subsystems as relatively independent control objects, or simply perform superposition control, failing to deeply consider and utilize the dynamic coupling characteristics of their real-time changes during faults. This "decoupling" or "static coordination" control approach is ill-suited to the strong nonlinearity and rapid time-varying nature of transient processes in AC / DC hybrid systems, potentially leading to control response lag, mutual cancellation of control actions by different devices, or even negative interactions, thus limiting the effectiveness of overvoltage suppression and the improvement of system stability margin.

[0004] Therefore, there is a significant gap and demand in existing technologies: there is an urgent need for a method that can perceive and quantify the dynamic coupling relationship between AC and DC subsystems in real time from a global system energy perspective, and on this basis, proactively plan and execute multi-timescale, multi-type resource (covering reactive and active) coordinated control. The goal of this method should not be limited to rapidly correcting voltage deviations, but should focus on the proactive and coordinated dissipation and guidance of excess electromagnetic energy during transient processes, thereby fundamentally enhancing the inherent ability of AC / DC hybrid power systems to withstand severe faults and suppress transient overvoltages. Summary of the Invention

[0005] The purpose of this invention is to provide a method for coordinated suppression and control of transient overvoltage in AC / DC hybrid power systems. By introducing coordinated scheduling of reactive and active resources based on global transient energy observation, the method significantly improves the suppression effect and dynamic stability of transient overvoltage in AC / DC hybrid power systems, and solves the problems of delayed suppression response and insufficient effect caused by the single control target and lack of coordinated resource scheduling in existing methods.

[0006] To address the aforementioned technical problems, a first aspect of this invention provides a method for coordinated suppression and control of transient overvoltage in an AC / DC hybrid power system, comprising the following steps: determining the transient electromagnetic energy level of the system based on real-time electrical quantity data collected during a fault in the AC / DC hybrid power system, wherein the transient electromagnetic energy level is used to quantify the scalar or function value of excess electromagnetic energy in the AC / DC hybrid power system after the fault; in response to the transient electromagnetic energy level exceeding a preset threshold, generating a coordinated control instruction set online with the optimization objective of minimizing the transient electromagnetic energy level, wherein the coordinated control instruction set includes a first type of instruction for scheduling reactive power regulation resources and a second type of instruction for scheduling active power regulation resources, wherein the active power regulation resources include at least a DC transmission system capable of emergency power modulation; and executing the coordinated control instruction set according to a preset timing logic to reduce the transient electromagnetic energy and suppress transient overvoltage.

[0007] Furthermore, determining the transient electromagnetic energy level of the system based on real-time electrical quantity data collected during a fault in the AC / DC hybrid power system includes: calculating the transient electromagnetic energy of the AC subsystem after fault clearance based on real-time collected AC bus voltage and current data, as the first component energy; calculating the transient electromagnetic energy of the DC subsystem during a fault based on real-time collected DC line voltage and current data, as the second component energy; calculating the dynamic coupling degree, which characterizes the energy interaction intensity between the AC and DC subsystems, in real-time according to the operating status and interactive power data of the converter station in the AC / DC hybrid power system; and determining the transient electromagnetic energy level of the system through weighted comprehensive calculation based on the dynamic coupling degree, the first component energy, and the second component energy; wherein, in the weighted comprehensive calculation, the weight coefficients of the first component energy and the second component energy are dynamically adjusted by the dynamic coupling degree.

[0008] Further, the step of calculating the dynamic coupling degree, which characterizes the energy interaction intensity between the AC subsystem and the DC subsystem, in real time based on the operating status and interactive power data of the converter station in the AC / DC hybrid power system includes: obtaining the interactive power of the converter station at the current sampling time and the previous sampling time, wherein the interactive power is the active power value of the AC / DC energy exchange intensity transmitted through the converter station, and calculating the real-time rate of change of the interactive power; obtaining the values ​​of the first component energy and the second component energy at the current sampling time and the previous sampling time, and calculating the real-time rate of change of the first component energy and the second component energy respectively; calculating the ratio of the real-time rate of change of the interactive power to the sum of the real-time rate of change of the first component energy and the real-time rate of change of the second component energy to obtain a dynamic coupling degree benchmark value; and normalizing the benchmark value of the dynamic coupling degree to obtain the dynamic coupling degree characterizing the energy interaction intensity.

[0009] Further, determining the transient electromagnetic energy level of the system based on the dynamic coupling degree, the first component energy, and the second component energy through weighted comprehensive calculation includes: determining the dominant relationship between the first component energy and the second component energy in the comprehensive calculation according to the numerical range of the dynamic coupling degree, wherein the dominant relationship includes AC dominance, DC dominance, and balanced dominance; obtaining a first weighting coefficient of the first component energy and a second weighting coefficient of the second component energy corresponding to the current dynamic coupling degree through a preset weight mapping relationship based on the dominant relationship; weighting the first component energy using the first weighting coefficient to obtain a first weighted energy, and weighting the second component energy using the second weighting coefficient to obtain a second weighted energy; obtaining a weighted comprehensive energy value from the sum of the first weighted energy and the second weighted energy; and obtaining the transient electromagnetic energy level of the system from the weighted comprehensive energy value based on a preset energy level conversion function.

[0010] Furthermore, in response to the transient electromagnetic energy level exceeding a preset threshold, and with minimizing the transient electromagnetic energy level as the optimization objective, an online collaborative control instruction set is generated, including: determining the current collaborative control mode of the AC / DC hybrid power system based on the dynamic coupling degree; calculating reference values ​​for the control quantities of the reactive power regulation resources and the active power regulation resources according to the collaborative control mode and the ratio of the first component energy to the second component energy; decoupling the reference values ​​for the control quantities and allocating them to a first-stage instruction subset at a first time scale and a second-stage instruction subset at a second time scale according to the dynamic response time constants of the reactive power regulation resources and the active power regulation resources; and combining and modifying the first-stage instruction subset and the second-stage instruction subset to generate the collaborative control instruction set, under the condition of satisfying the voltage safety constraints and equipment overload constraints of the key nodes of the AC / DC hybrid power system.

[0011] Further, determining the current cooperative control mode of the AC / DC hybrid power system based on the dynamic coupling degree includes: acquiring the values ​​of the dynamic coupling degree at the current sampling time and the previous sampling time, and calculating the real-time rate of change of the dynamic coupling degree; weighting and fusing the value of the dynamic coupling degree with its real-time rate of change to calculate the cooperative control dominance index; mapping the cooperative control dominance index to the corresponding cooperative control mode according to a preset threshold range, wherein the first threshold range corresponds to the cooperative control mode dominated by the AC subsystem, the second threshold range corresponds to the cooperative control mode dominated by the DC subsystem, and the third threshold range corresponds to the AC / DC balanced cooperative control mode.

[0012] Further, the step of calculating the control quantity reference values ​​of the reactive power regulation resource and the active power regulation resource based on the cooperative control mode and the ratio of the first component energy to the second component energy includes: determining the target allocation weights of the reactive power regulation resource and the active power regulation resource for dissipated energy based on the cooperative control mode; calculating the target energy value that needs to be dissipated jointly by the reactive power regulation resource and the active power regulation resource according to the ratio of the first component energy to the second component energy; and decomposing the target energy value into a reactive power reference value of the reactive power regulation resource and an active power modulation reference value of the active power regulation resource according to the target allocation weights.

[0013] Further, determining the target allocation weights of the reactive power regulation resources and the active power regulation resources for dissipated energy based on the cooperative control mode includes: obtaining preset initial weight benchmark values ​​for the reactive power regulation resources and the active power regulation resources based on the cooperative control mode; obtaining the dynamic reactive power reserve capacity and response speed scores of key equipment in the reactive power regulation resources in real time, and calculating the comprehensive availability index of the reactive power regulation resources; obtaining the modulotable active power capacity and modulation rate scores of key equipment in the active power regulation resources in real time, and calculating the comprehensive availability index of the active power regulation resources; dynamically correcting the initial weight benchmark values ​​according to the ratio of the comprehensive availability index of the reactive power regulation resources to the comprehensive availability index of the active power regulation resources; and normalizing the corrected weight values ​​to obtain the target allocation weights of the reactive power regulation resources and the active power regulation resources.

[0014] Further, the step of decoupling and allocating the control quantity reference value to a first-stage instruction subset at a first time scale and a second-stage instruction subset at a second time scale includes: identifying fast-response devices and slow-response devices based on the dynamic response time constants of the reactive power regulation resources and the active power regulation resources; allocating the control quantity reference value for the fast-response devices to the first-stage instruction subset; and allocating the control quantity reference value for the slow-response devices, as well as the corrective control quantity added to the fast-response devices to optimize the control effect, to the second-stage instruction subset.

[0015] Further, the step of executing the coordinated control instruction set according to a preset timing logic to reduce the transient electromagnetic energy and suppress transient overvoltage includes: sending a first-stage instruction subset to the fast-response devices in the reactive power regulation resources to provide emergency reactive power support within the first time scale; after starting the execution of the first-stage instruction subset, sending a second-stage instruction subset to the active power regulation resources and the slow-response devices in the reactive power regulation resources to achieve active power redistribution and secondary reactive power regulation within the second time scale; during the execution of the first-stage instruction subset and the second-stage instruction subset, monitoring in real time the rate of change of the transient electromagnetic energy level and the voltage deviation of key nodes in the AC / DC hybrid power system; dynamically adjusting the control parameter setting values ​​or issuance timing of the instructions in the second-stage instruction subset according to the rate of change and the voltage deviation; and stopping the execution of the coordinated control instruction set when the transient electromagnetic energy level drops below the preset threshold and the voltage of the key node recovers to the preset safe range.

[0016] Accordingly, a second aspect of the present invention provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the above-described AC / DC hybrid power system transient overvoltage collaborative suppression control method.

[0017] Accordingly, a third aspect of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described AC / DC hybrid power system transient overvoltage collaborative suppression control method.

[0018] The above-mentioned technical solutions of the present invention have the following beneficial technical effects: 1. By expanding the control dimension of transient overvoltage suppression from the traditional single reactive power regulation to multi-objective collaborative scheduling of reactive and active resources based on real-time observation of system transient electromagnetic energy, and establishing a complete control closed loop from "energy observation - path planning - timing execution", the active and multi-channel dissipation and guidance of excess energy in the system after a fault are realized; it not only effectively suppresses the rise in voltage amplitude, but also improves the transient stability limit of the system from the root of energy balance, solving the problem that the suppression effect of existing methods is limited due to the single control objective and failure to perform global optimization from the system energy level; 2. By calculating and dynamically quantifying the energy interaction intensity (dynamic coupling degree) between AC and DC subsystems in real time, and using this as the core criterion to dynamically determine the collaborative control mode and the comprehensive weight of each component energy, the control strategy can automatically adapt to the inherent coupling characteristics of the system under different fault scenarios and operating conditions; it significantly enhances the adaptability and accuracy of the control strategy, and solves the problem of control command mismatch, poor response effect, or even negative interaction caused by ignoring or simplifying the AC and DC dynamic coupling relationship in existing methods; 3. By constructing a hierarchical collaborative execution architecture that "determines target allocation weights based on operating status, decouples commands into multiple time scales according to equipment response speed, and dynamically fine-tunes them based on real-time feedback during execution," this method achieves an organic unity between rapid emergency support and slow, refined adjustment, as well as online safety verification and closed-loop correction of control commands. It significantly improves the dynamic response speed, overall coordination, and operational reliability of the control system, and solves the safety hazards of rigid control timing, uncoordinated equipment responses, and potential over-limit operations in traditional methods. Attached Figure Description

[0019] Figure 1 is a flowchart of the AC / DC hybrid power system transient overvoltage collaborative suppression control method provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0021] The AC / DC hybrid power system transient overvoltage collaborative suppression and control method provided in the first aspect of this invention is applicable to AC / DC hybrid power systems that include high-voltage DC transmission projects and centralized access to new energy sources. In such systems, when severe disturbances occur, such as AC line short-circuit faults and disconnection, large-capacity unit tripping, or DC system blockage, the system power flow will shift drastically, potentially leading to transient or continuous power frequency overvoltage problems in the receiving-end grid, seriously threatening equipment insulation safety and system stable operation. Traditional methods relying on fixed switching reactive power compensation or single regulation methods are insufficient to quickly, economically, and collaboratively address such complex transient processes.

[0022] Please refer to Figure 1. The above-mentioned AC / DC hybrid power system transient overvoltage collaborative suppression control method specifically includes the following steps: Step S100, based on the electrical quantity data collected in real time during the fault of the AC / DC hybrid power system, the transient electromagnetic energy level of the system is determined. The transient electromagnetic energy level is used to quantify the scalar or function value of the excess electromagnetic energy in the AC / DC hybrid power system after the fault.

[0023] The transient electromagnetic energy level is a key state indicator used to comprehensively quantify excess electromagnetic energy in an AC / DC hybrid system after a fault. In practice, it utilizes a wide-area measurement system to acquire real-time synchronous data such as voltage phasors at key nodes, current phasors in important lines, and electromotive force angles within generators after the fault. The calculation of the transient electromagnetic energy level is typically based on Lyapunov's energy function or related variations, its core being the calculation of the "energy difference" between the system's current operating point (near the unstable equilibrium point after the fault) and the stable equilibrium point before or during the fault. This calculation process integrates node voltage amplitude deviations, generator rotor kinetic energy, and the electromagnetic energy stored in the network, ultimately outputting a scalar or function value that characterizes the degree of system deviation from a steady state and is positively correlated with the severity of overvoltage. A higher level indicates a greater accumulation of excess electromagnetic energy in the system, potentially leading to a sustained voltage increase, and a more prominent risk of transient overvoltage.

[0024] Step S200: In response to the transient electromagnetic energy level exceeding a preset threshold, a coordinated control instruction set is generated online with the goal of minimizing the transient electromagnetic energy level. The coordinated control instruction set includes a first type of instruction for scheduling reactive power regulation resources and a second type of instruction for scheduling active power regulation resources. The active power regulation resources include at least a DC transmission system capable of emergency power modulation.

[0025] The preset threshold is determined based on system safety and stability guidelines and simulation analysis. Once exceeded, coordinated optimization control is triggered. The optimization control model uses the rapid minimization of the transient electromagnetic energy level calculated in step S100 as the core objective function. Its decision variables cover all rapidly dispatchable reactive and active power regulation resources in the system. The generated coordinated control instruction set includes two main categories: the first category targets reactive power regulation resources, used to dispatch the capacitive or inductive reactive power output of dynamic reactive power sources such as static var compensators, static synchronous compensators, and synchronous condensers to directly absorb excess reactive power and regulate node voltage; the second category targets active power regulation resources, the core of which is to dispatch DC transmission systems capable of emergency power modulation, for example, by increasing or decreasing DC transmission power to change the power flow distribution of the AC network, thereby indirectly affecting the reactive power balance and voltage level of the system. The optimization process is conducted online and on a rolling basis. It needs to meet the physical constraints of various regulation resources (such as capacity limits and ramp rates) and system operation constraints, and finally solve for a set of control instructions that coordinates reactive and active power resources to minimize the transient electromagnetic energy level.

[0026] In step S300, according to the preset timing logic, a set of cooperative control instructions is executed to reduce transient electromagnetic energy and suppress transient overvoltage.

[0027] The preset timing logic considers the dynamic response characteristics of different regulation resources. Typically, the dynamic reactive power compensation device has the fastest response speed (milliseconds). Therefore, the first type of instruction (reactive power regulation) is executed first and quickly to immediately absorb local excess reactive power and initially curb the voltage rise. Subsequently, the second type of instruction (active power regulation, mainly DC power modulation) is executed at a slightly later but closely connected time. Although DC power adjustment has a certain inertia, its regulation capacity is large and its impact is wide-ranging, capable of changing the system power balance at a global level and addressing the root cause of overvoltage at a deeper level. The entire execution process is closed-loop: while executing instructions, the system continuously monitors changes in transient electromagnetic energy levels and can perform feedback correction based on the new system state. By executing the optimized instruction set according to the timing logic of "reactive power first, active power second, and mutual coordination," the system can rapidly dissipate excess electromagnetic energy accumulated after a fault in stages and multiple dimensions, thereby achieving effective and stable suppression of transient overvoltage.

[0028] Through the above steps, a closed-loop active defense mechanism for transient overvoltage, consisting of "real-time assessment, online optimization, and collaborative execution," is constructed. This method overcomes the limitations of traditional single, passive control measures. By introducing a unified index characterizing the overall energy state of the system and using this index as a target to coordinate and schedule cross-regional, multi-type control resources, including fast reactive power sources and modulated DC systems, it achieves rapid, accurate, and collaborative suppression of transient overvoltage problems in AC / DC hybrid systems, significantly improving the system's voltage stability and operational recovery capability after severe faults.

[0029] Specifically, step S100, which determines the transient electromagnetic energy level of the system based on the electrical quantity data collected in real time during the fault of the AC / DC hybrid power system, includes: step S110, calculating the transient electromagnetic energy of the AC subsystem after the fault is cleared based on the real-time collected AC bus voltage and current data, as the first component energy.

[0030] In practice, the system acquires the three-phase voltage phasors of critical AC buses and the three-phase current phasors of connected lines immediately after fault clearance and during the subsequent transient process through a wide-area measurement system. The calculation of the first component energy is based on the transient energy function theory, the core of which is to calculate the excess electromagnetic energy stored in the system during the process of the AC network recovering from the current operating state after the fault to a certain reference stable equilibrium point (usually the steady state before the fault or the feasible equilibrium point after the fault). The calculation usually involves the integration or summation of the changes in energy stored in inductive and capacitive elements in the network, such as calculating the relative kinetic energy change of the critical generator rotor, the increase in magnetic field energy in critical lines and transformers, and the increase in electric field energy in the bus-to-ground capacitance. This component energy directly reflects the scale of excess energy accumulated in the AC network itself due to fault disturbances, which may lead to voltage rise, and is the basis for assessing the risk of transient overvoltage.

[0031] Step S120: Based on the real-time collected DC line voltage and current data, calculate the transient electromagnetic energy of the DC subsystem during the fault period, as the second component energy.

[0032] For high-voltage direct current (HVDC) transmission systems, transient energy primarily manifests in the release of electromagnetic energy stored in DC lines and smoothing reactors after converter blocking or power interruption, as well as power surplus or shortage caused by the dynamic behavior of the DC control system during faults. The system collects real-time data on DC line pole voltages, pole currents, and the status of key switching quantities at the converter station. The calculation of the second component energy considers two parts: first, the energy change of energy storage components such as DC lines during fault disturbances; and second, the energy corresponding to the equivalent power surge injected or absorbed in the connected AC system due to sudden changes in DC power transmission (such as power interruption caused by commutation failure). This component energy quantifies the contribution of the dynamic behavior of the DC subsystem and its power interaction with the AC system to the overall transient energy balance, and is particularly crucial in receiving-end grids with multiple DC feeds.

[0033] Step S130: Based on the operating status and interactive power data of the converter station in the AC / DC hybrid power system, calculate in real time the dynamic coupling degree, which characterizes the energy interaction intensity between the AC subsystem and the DC subsystem.

[0034] Dynamic coupling is a dimensionless, real-time variable index used to quantify the degree of energy interaction between AC and DC systems during transient processes. Its calculation primarily relies on two real-time variables: first, the converter station's operating control mode and status (e.g., whether commutation failure has occurred, whether it is in a power recovery period, whether the control mode is constant power or constant voltage); and second, the magnitude and rate of change of active and reactive power exchanged between the AC and DC systems in real time. For example, when the DC system operates at rated power and is under stable control, the coupling degree may be high; when the DC system is blocked due to a fault or is in a power modulation process, the coupling degree will change dynamically. One calculation method is to normalize the absolute value or rate of change of the real-time AC / DC interaction power with the system's baseline capacity and combine it with converter station status information (e.g., 0 for blocking, 1 for normal operation) for comprehensive calculation. This index reflects in real time the strength of the DC system's voltage support or impact on the AC system as a "source" or "load".

[0035] Step S140: Based on the dynamic coupling degree, the first component energy, and the second component energy, the transient electromagnetic energy level of the system is determined through weighted synthesis calculation. In the weighted synthesis calculation, the weighting coefficients of the first component energy and the second component energy are dynamically adjusted by the dynamic coupling degree.

[0036] A pre-defined basic weight allocation is established. For example, when the coupling degree is extremely low (DC is essentially decoupled), the weights are entirely biased towards the first energy component; when the coupling degree is extremely high (DC is strongly correlated), the weights are relatively balanced between the two. Specifically, the weighting coefficient α of the first energy component and the weighting coefficient β of the second energy component are dynamically calculated using a function with dynamic coupling degree as the independent variable, satisfying α + β = 1. The transient electromagnetic energy level E of the system is...level The final calculation is as follows: E ac For the first component energy, E dc The second component is energy. When the AC / DC coupling is tight, the transient energy of the DC subsystem is fully included in the overall level assessment; when the coupling is loose, the assessment is mainly based on the energy of the AC subsystem. This overcomes the assessment inaccuracies caused by the traditional method of separately assessing the AC / DC system or using fixed weighting, enabling the final determined transient electromagnetic energy level to more accurately characterize the true energy excess state and overvoltage risk of the entire AC / DC hybrid system.

[0037] Further, step S130, which calculates the dynamic coupling degree characterizing the energy interaction intensity between the AC subsystem and the DC subsystem in real time based on the operating status and interactive power data of the converter station in the AC / DC hybrid power system, includes: step S131, obtaining the interactive power of the converter station at the current sampling time and the previous sampling time, where the interactive power is the active power value of the AC / DC energy exchange intensity transmitted through the converter station, and calculating the real-time rate of change of the interactive power.

[0038] Interactive power specifically refers to the active power value transmitted through the converter station, used to quantify the intensity of energy exchange between AC and DC systems. It is typically defined as the active power injected from the DC system to the AC system in the positive direction. The system obtains continuous sampling values ​​of this power in real time from the converter station's control and protection system. The real-time rate of change of interactive power is obtained by calculating the difference between the power value at the current sampling moment and the power value at the previous sampling moment, and then dividing by the sampling time interval. This rate of change physically characterizes the rate of increase or decrease of energy transmitted through the converter station interface per unit time. The larger its absolute value, the more drastic the power impact or support effect of the DC system on the AC system changes in a short period of time. For example, when a fault occurs on the AC side causing commutation failure in the DC system, the interactive power may drop sharply to zero or even reverse within milliseconds. In this case, the calculated rate of change will be a very large negative value, directly reflecting the abrupt interruption of energy exchange at the AC-DC coupling interface at the moment of the fault.

[0039] Step S132: Obtain the values ​​of the first component energy and the second component energy at the current sampling time and the previous sampling time, and calculate the real-time change rate of the first component energy and the second component energy respectively.

[0040] The first and second energy components are defined and calculated as described in steps S110 and S120, respectively. The system updates these two energy values ​​at each sampling time. The calculation of their real-time change rate is similar to that of the interactive power change rate, i.e., subtracting the energy value from the previous time step from the current energy value, and then dividing by the sampling interval. The change rate of the first energy component reflects the accumulation or dissipation rate of transient electromagnetic energy in the AC subsystem; the change rate of the second energy component reflects the change rate of transient electromagnetic energy in the DC subsystem. During transient processes, such as after fault clearance, if the AC system has excess reactive power and the bus voltage rises, the first energy component may increase rapidly, with a positive and relatively large change rate; simultaneously, the DC system may be in a power recovery or modulation state, and its transient energy (second energy component) is also changing. The sum of these two energy change rates quantifies the instantaneous change trend of the total transient electromagnetic energy of the AC / DC hybrid system.

[0041] Step S133: Calculate the ratio of the real-time change rate of the interactive power to the sum of the real-time change rates of the first component energy and the second component energy to obtain the dynamic coupling degree benchmark value.

[0042] Dynamic coupling baseline value (denoted as K) base The formula for calculating K is: base =∣ΔP 交互 ∣ / (∣ΔE ac |+|ΔE dc The ratio ∣) represents the sum of the absolute values ​​of the rate of change of the interactive power at the converter station interface and the sum of the absolute values ​​of the rates of change of the two energy components. This ratio measures the proportion of the change in power interaction at the converter station interface (the "cause") to the total transient energy change of the entire system (the "effect") per unit time. A larger ratio indicates that the dynamic interaction of power at the AC / DC interface is the main driver of the total energy change in the system, meaning that the two subsystems are tightly coupled and have a strong mutual influence. A smaller ratio indicates that the change in the total energy of the system mainly originates from the dynamics within the AC or DC subsystem, and the coupling between AC and DC is relatively weak. This benchmark value provides a dimensionless, quantitative instantaneous measure of coupling strength from the perspective of energy flow.

[0043] Step S134: Normalize the baseline value of the dynamic coupling degree to obtain the dynamic coupling degree characterizing the energy interaction intensity.

[0044] Because of the calculated benchmark value K base Its numerical range may vary depending on the system size, operating conditions, and the magnitude of disturbances. To obtain a stable, comparable, and easily usable index, normalization is necessary. Normalization is typically based on a preset reference value. One implementation method is to pre-set a maximum baseline reference value K that may occur under extreme operating conditions, based on historical severe fault simulations or theoretical analysis.max The final dynamic coupling degree K used in step S140 is calculated as: K = min(K base / K max This operation restricts the dynamic coupling degree K to a closed interval of [0, 1.0]. When K is close to 1.0, it indicates that the current AC / DC energy interaction intensity has reached or is close to the preset extremely tight coupling level; when K is close to 0, it indicates that the coupling is very weak. This normalization process makes the dynamic coupling degree a standardized and robust intermediate variable, providing a stable and consistent input for the dynamic adjustment of weights in subsequent steps.

[0045] Through continuous calculations in steps S131 to S134, this invention constructs a dynamic coupling quantification method based on real-time energy change rate. This method abandons the traditional simplistic judgment based on topological connectivity or steady-state power flow, instead focusing on the ratio of the most fundamental energy interaction rate to the total energy change rate of the system during transient processes. This enables real-time, accurate, and data-driven measurement of the dynamic coupling strength between AC and DC systems. This provides crucial scientific basis for the adaptive fusion of AC and DC transient energy components based on coupling strength in step S140, ensuring that the overall transient electromagnetic energy level assessment can keenly capture and reflect the instantaneous changes in AC-DC interaction strength, thereby significantly improving the accuracy and adaptability of subsequent collaborative suppression control strategy generation.

[0046] Further, in step S140, the transient electromagnetic energy level of the system is determined by weighted comprehensive calculation based on the dynamic coupling degree, the first component energy, and the second component energy. This includes step S141, determining the dominant relationship between the first component energy and the second component energy in the comprehensive calculation according to the numerical range of the dynamic coupling degree. The dominant relationship includes AC dominance, DC dominance, and balanced dominance.

[0047] The dynamic coupling degree is a normalized scalar value between 0 and 1. The system determines the current AC / DC energy interaction mode based on the preset range in which this value falls. For example, when the dynamic coupling degree is less than threshold A (e.g., 0.3), it is determined to be an "AC-dominated" relationship, indicating that the transient energy change of the system mainly originates from the dynamic process within the AC subsystem, while the influence of the DC subsystem is weak. When the dynamic coupling degree is greater than threshold B (e.g., 0.7), it is determined to be a "DC-dominated" relationship, indicating that the power interaction dynamics of the DC subsystem are the core factor driving the transient energy change of the system. When the dynamic coupling degree is between threshold A and threshold B, it is determined to be a "balanced-dominated" relationship, indicating that the contributions of the AC and DC subsystems to the transient energy change are roughly equal, and the two influence each other closely. This qualitative judgment of the dominant relationship based on real-time coupling strength provides a logical basis for subsequent differentiated weight allocation.

[0048] Step S142: Based on the dominant relationship, obtain the first weight coefficient of the first component energy and the second weight coefficient of the second component energy corresponding to the current dynamic coupling degree through a preset weight mapping relationship.

[0049] The system pre-defines weighting coefficient mapping rules corresponding to three relationships: "AC-dominant," "DC-dominant," and "balanced-dominant." These rules are typically expressed as a continuous or piecewise function with dynamic coupling degree as the independent variable. For the "AC-dominant" interval, the mapping function keeps the first weighting coefficient (corresponding to the AC component) at a high value (e.g., close to 0.8 or higher), while the second weighting coefficient (corresponding to the DC component) is lower. For the "DC-dominant" interval, the function exhibits the opposite characteristic, with the second weighting coefficient significantly increasing. In the intermediate transition interval of "balanced-dominant," the two weighting coefficients change continuously with the dynamic coupling degree, taking values ​​close to each other. For example, linear interpolation or an S-curve function can be used to ensure a smooth transition of the weighting coefficients with changes in coupling degree, avoiding jumps. Finally, based on the currently calculated specific value of the dynamic coupling degree, the system obtains a pair of first weighting coefficients α and second weighting coefficients β that sum to 1 in real time through a query function or calculation.

[0050] Step S143: The first component energy is weighted using the first weighting coefficient to obtain the first weighted energy, and the second component energy is weighted using the second weighting coefficient to obtain the second weighted energy. The weighted comprehensive energy value is obtained by summing the first weighted energy and the second weighted energy.

[0051] This step performs a specific weighted composite calculation. The system will use the first component energy (E) calculated in step S110. ac Multiplying this by the first weighting coefficient α obtained in step S142 yields the first weighted energy. Similarly, the second component energy (E) calculated in step S120 is... dc Multiplying this by the second weighting coefficient β yields the second weighted energy. Then, the two weighted energy values ​​are added together, and the sum is the weighted composite energy value. This calculation process does not simply add the energies of the two subsystems together, but rather integrates them with a focus on their actual impact on the overall transient behavior of the current system (reflected by the weights determined by the dynamic coupling degree). When the coupling degree is low and AC dominates, the comprehensive energy value mainly reflects AC energy; when the coupling degree is high, the influence of DC energy is fully incorporated.

[0052] Step S144: Based on the preset energy level conversion function, the transient electromagnetic energy level of the system is obtained from the weighted comprehensive energy value.

[0053] While the weighted composite energy value incorporates both AC and DC components, its absolute magnitude and dimensions may not be suitable for direct threshold comparison and control decisions. Therefore, a pre-defined energy level conversion function is needed to map it to a standardized, dimensionless, or physically meaningful "transient electromagnetic energy level" index. This conversion function could be a linear scaling function, for example, scaling E... composite In addition to its reference value under typical severe faults, it may also be a nonlinear function designed to assign different sensitivities to low-energy and high-energy regions. The purpose of the transformation is to generate a final index with a relatively fixed range (e.g., between 0 and 1 or between 0 and a certain upper limit) whose numerical growth is monotonically correlated with the system overvoltage risk. This final output, the "transient electromagnetic energy level," is a unified scalar that quantitatively and comprehensively characterizes the overall level of excess electromagnetic energy accumulated in the entire hybrid power system under the current AC / DC coupling state, which may trigger transient overvoltages. This provides an accurate and reliable input for control triggering and optimization in step S200.

[0054] Based on real-time coupling strength, the dominant source of energy change is determined, and then weighted and synthesized through an adaptive weight allocation mechanism, finally transforming it into a unified situation indicator. This method overcomes the shortcomings of fixed-weight or simple superposition evaluation methods, ensuring that the evaluated overall transient electromagnetic energy level of the system can accurately and sensitively reflect the dominant risk source and its severity, regardless of whether it is dominated by AC faults, DC disturbances, or complex transient scenarios with strong coupling interactions. This lays a crucial perceptual foundation for the subsequent generation of accurate and coordinated overvoltage suppression control strategies, significantly improving the targeting and overall effectiveness of control.

[0055] Specifically, in step S200, in response to the transient electromagnetic energy level exceeding a preset threshold, a set of cooperative control instructions is generated online with the goal of minimizing the transient electromagnetic energy level. This includes step S210, which determines the current cooperative control mode of the AC / DC hybrid power system based on the dynamic coupling degree.

[0056] Dynamic coupling measures the degree of energy interaction between the AC and DC subsystems during transient processes and is a key basis for selecting the dominant control strategy. The system presets several typical cooperative control modes corresponding to the dynamic coupling degree value ranges. For example, when the dynamic coupling degree is below the lower threshold (e.g., 0.2), the system is determined to be in the "AC-side dominant control mode." In this mode, transient energy is mainly caused by the internal dynamics of the AC subsystem, with minimal influence from the DC subsystem. Therefore, the control strategy will primarily focus on rapidly switching or adjusting the reactive power compensation devices on the AC side. When the dynamic coupling degree is above the upper threshold (e.g., 0.8), the system is determined to be in the "DC-side dominant control mode," indicating that drastic power fluctuations in the DC subsystem are the main cause of excess system energy. The core of the control strategy will be to change the global power flow through emergency modulation of DC power. When the dynamic coupling degree is in the middle range, it is determined to be in the "AC-DC strong coupling cooperative mode." In this case, it is necessary to coordinate the reactive power resources on the AC side and the active power modulation on the DC side to implement joint control. The real-time determination of the control mode provides a clear strategic guide for subsequent resource allocation.

[0057] Step S220: Based on the cooperative control mode and the ratio of the first component energy to the second component energy, calculate the reference values ​​of the control quantities of reactive power regulation resources and active power regulation resources.

[0058] Under the established control mode, the calculation of control variables is further refined. The system analyzes the first component energy (E). ac ) and the second component energy (E) dc The current value of ) and its proportional relationship (e.g., E) ac / E total For reactive power regulation resources (such as SVC, STATCOM, synchronous condensers), their control reference values ​​(such as the required reactive power output Q) are... ref The calculation of reactive power is mainly related to the magnitude of the first component energy and the current AC bus voltage deviation, aiming to quickly inject or absorb reactive power to balance the AC network. For active power regulation resources (the core of which is the DC transmission system), its control quantity reference value (such as DC power modulation quantity ΔP) dc_ref The calculation of ) is more closely related to the magnitude of the second component energy and the dynamic coupling degree, aiming to regulate the AC / DC interface power flow by changing the transmission power. Under the "AC / DC strong coupling cooperative mode", the control reference values ​​of both will be based on E ac With E dc The proportions are calculated collaboratively to ensure that each entity's "energy neutralization" task matches its source contribution.

[0059] Step S230: Based on the dynamic response time constants of reactive power regulation resources and active power regulation resources, the control quantity reference value is decoupled and allocated to the first-stage instruction subset of the first time scale and the second-stage instruction subset of the second time scale.

[0060] The physical inertia of different control devices varies significantly. Dynamic reactive power compensation devices (such as STATCOM) typically have response time constants ranging from several milliseconds to tens of milliseconds, classifying them as extremely fast-response resources. In contrast, power modulation in DC transmission systems involves processes such as control system command transmission and converter valve firing angle adjustment, with effective response time constants typically ranging from tens to hundreds of milliseconds, classifying them as fast but relatively slower resources. Based on this, the system decouples control reference values ​​according to time scales: control commands for fast reactive power resources like STATCOM are allocated to form a "first-stage command subset on the first time scale," aiming to achieve initial rapid suppression of transient voltage. Control commands for DC power modulation are allocated to form a "second-stage command subset on the second time scale," aiming to implement deeper and wider-ranging energy rebalancing within a later time window to consolidate control effects and prevent voltage rebound. This time-sequential decoupling allocation is crucial for achieving physical coordination.

[0061] Step S240: Under the condition of satisfying the voltage safety constraints and equipment overload constraints of the key nodes of the AC / DC hybrid power system, the first-stage instruction subset and the second-stage instruction subset are combined and modified to generate a coordinated control instruction set.

[0062] When combining the two initially allocated subsets of instructions, an online optimization and verification process must be implemented to ensure that their execution does not introduce new safety issues. The optimization and verification model focuses on minimizing transient electromagnetic energy levels while incorporating strict constraints, including: the voltage of key nodes (such as the converter buses at the sending and receiving ends and new energy collection points) must remain within safe upper and lower limits during dynamic processes; the output of all invoked reactive power compensation devices must not exceed their instantaneous capacity limits; and the DC power modulation amount must be within its permissible emergency modulation range, with the rate of change not exceeding the equipment's tolerance. This optimization process may fine-tune the initial instruction values, for example, by further increasing reactive power absorption instructions when the voltage approaches its upper limit, or by limiting the modulation depth of a DC line when it is nearing its thermal stability limit. Ultimately, the output is a complete "cooperative control instruction set" that has undergone safety verification, timing coordination, and is technically executable.

[0063] Starting from the dynamic coupling state of the system, the control mode is determined, control quantities are allocated according to the energy composition, the timing is decoupled based on the physical response characteristics, and finally an executable scheme is formed through rigorous safety optimization verification. This process ensures that the generated instruction set not only has a clear objective (minimizing transient energy) but also is highly adapted to the real-time operating conditions of the system, with clear priorities in resource allocation, orderly timing, and strict control over execution safety. This overcomes the blindness and limitations of traditional pre-planned control or single-resource regulation, providing core decision support for implementing rapid, accurate, and robust collaborative active suppression of transient overvoltages in complex AC / DC hybrid power grids.

[0064] Further, step S210, which determines the current cooperative control mode of the AC / DC hybrid power system based on the dynamic coupling degree, includes: step S211, obtaining the values ​​of the dynamic coupling degree at the current sampling time and the previous sampling time, and calculating the real-time rate of change of the dynamic coupling degree. The dynamic coupling degree is a continuous variable reflecting the change of energy interaction intensity between AC and DC subsystems over time. The system continuously reads the latest value (K) of this coupling degree from the real-time calculation unit. n ) and the value of the previous sampling period (K) n-1 The real-time rate of change (ΔK / Δt) is obtained by calculating the difference between the current value and the previous value, and then dividing it by a fixed sampling time interval (Δt). This rate of change quantifies the rate of increase or decrease in coupling strength per unit time. Its sign (positive or negative) indicates whether the coupling strength is increasing or decreasing, while the absolute value reflects the degree of drastic change. For example, after an AC-side fault causes a DC commutation failure, the dynamic coupling degree may drop to an extremely low value instantly, at which point its rate of change is a large negative value; while during an emergency DC power recovery, the coupling degree may rise rapidly, and the rate of change becomes positive and relatively large. Calculating the rate of change is to capture the development trend of the coupling state and provide dynamic information for judging the evolution direction of the control mode.

[0065] Step S212: The value of dynamic coupling degree is weighted and fused with its real-time rate of change to calculate the collaborative control dominance index.

[0066] By constructing a comprehensive decision index that reflects both the current coupling strength and its changing trend, preset weighting coefficients ω1 and ω2 (ω1+ω2=1) are assigned to the current value (K) of the dynamic coupling degree and its rate of change (ΔK / Δt), respectively. The setting of these weighting coefficients reflects a balance between the emphasis on "current state" and "changing trend." For example, in scenarios emphasizing rapid response, a higher weight might be assigned to the rate of change. The collaborative control dominance index (I...) d ) Calculated by weighted summation: I d =ω1 K+ω2 f(ΔK / Δt), where f() may be a normalization or scaling function used to process the rate of change to a dimension or numerical range matching K. When the dynamic coupling degree itself is high and rapidly increasing, the calculated dominance index will significantly increase, indicating that the AC / DC coupling effect is rapidly becoming the dominant factor in the system's transient behavior; conversely, the index will decrease. This index combines static strength and dynamic trend, providing a more robust and forward-looking basis for mode determination.

[0067] Step S213: Based on the preset threshold range of the cooperative control dominance index, map the cooperative control dominance index to the corresponding cooperative control mode, wherein the first threshold range corresponds to the cooperative control mode dominated by the AC subsystem, the second threshold range corresponds to the cooperative control mode dominated by the DC subsystem, and the third threshold range corresponds to the AC / DC balanced cooperative control mode.

[0068] Based on extensive offline simulation analysis, stability studies, and operational experience, several threshold boundaries for dominance indices are preset, thus dividing the continuous index range into several discrete intervals. For example, the first threshold interval is set when the index is below the lower limit L1. This interval corresponds to a "cooperative control mode dominated by the AC subsystem," indicating that the current system transient process is mainly driven by AC dynamics, with weak DC influence. The control strategy should focus on rapidly adjusting AC reactive power resources. The second threshold interval is set when the index is above the upper limit L2. This interval corresponds to a "cooperative control mode dominated by the DC subsystem," indicating that DC power dynamics are the main contradiction causing and dominating system transient energy. The control strategy should prioritize and emphasize the use of DC power modulation capabilities. The third threshold interval, between L1 and L2, corresponds to an "AC / DC balanced cooperative control mode," indicating that the contributions and influences of the two subsystems on the transient process are closely intertwined. A control strategy that emphasizes both reactive and active power resources and deep coordination must be adopted. By querying the threshold interval to which the dominance index belongs in real time, the system can automatically and clearly determine the cooperative control mode to be adopted.

[0069] It not only relies on the instantaneous value of coupling strength, but also captures its dynamic direction by introducing the rate of change, and forms a comprehensive decision index through weighted fusion. Finally, it maps to specific control modes through clear threshold logic. This ensures that the selection of cooperative control modes can more sensitively reflect and predict the transfer and evolution of the dominant contradiction during system transient processes. This provides key and adaptive strategic guidance for the precise allocation of subsequent control resources and the generation of cooperative action sequences, significantly enhancing the adaptability and control effectiveness of the entire cooperative suppression control system to complex AC / DC transient processes.

[0070] Further, in step S220, the reference values ​​for the control quantities of reactive power regulation resources and active power regulation resources are calculated based on the cooperative control mode and the ratio of the first component energy to the second component energy. This includes step S221, which determines the target allocation weights of reactive power regulation resources and active power regulation resources for dissipated energy based on the cooperative control mode.

[0071] The coordinated control mode (AC-dominant, DC-dominant, or balanced coordinated) essentially indicates which type of regulation resource should bear the primary responsibility for energy dissipation under the current transient scenario. The system pre-sets corresponding weighting coefficient pairs (W) for each mode. q W p), where W q W represents the allocation weight of reactive power regulation resources (such as SVC, STATCOM). p This represents the allocation weight of active power regulation resources (mainly DC power modulation) and satisfies W q +W p = 1. Under the "cooperative control mode dominated by the communication subsystem", the weight setting is usually W. q Significantly greater than W p (For example, 0.8:0.2), emphasizing the use of fast reactive power equipment to balance excess reactive power locally. Under the "DC subsystem-dominated cooperative control mode," the weighting is reversed, W... p Significantly greater than W q (e.g., 0.2:0.8), emphasizing the elimination of the root cause of energy excess by modifying DC power to change the system's power flow distribution at a global level. Under the "AC / DC balanced coordinated control mode," the weight settings tend to be balanced (e.g., 0.5:0.5), requiring the two types of resources to collaboratively share the dissipation task. These weights provide a proportional basis for the decomposition of the target energy.

[0072] Step S222: Calculate the target energy value that needs to be dissipated by both reactive power regulation resources and active power regulation resources, based on the ratio of the first component energy to the second component energy.

[0073] First component energy (E) ac ) and the second component energy (E) dc The proportion of (e.g., E) ac / E total This reveals the source and composition of the current system's excess energy. The target energy value is not simply equal to the total transient electromagnetic energy level, but rather the "effective control energy" that needs to be dissipated to bring the system back to a safe state. Its calculation considers the contribution of the two energy components to the overall level and the energy efficiency relationship of system recovery. One implementation is that the target energy value (E...) target ) is calculated as a weighted composite energy value (E) composite A proportional function of E, which takes into account the current voltage deviation and the mixing ratio of the two types of energy. For example, when E ac When E is dominant, it indicates that the excess energy is mainly manifested as localized reactive power excess, and the proportion of the target energy value that needs to be dissipated by reactive power resources will increase accordingly; conversely, when E is dominant... dc When the dominant energy level is reached, the target energy value becomes more relevant to the global energy imbalance that needs to be adjusted through active power modulation. This step ensures that the energy target to be dissipated matches the physical nature of the current energy surplus.

[0074] Step S223: Based on the target allocation weight, the target energy value is decomposed into the reactive power reference value of the reactive power regulation resource and the active power modulation reference value of the active power regulation resource.

[0075] The abstract energy target is transformed into specific, executable control command values. First, based on the weighting coefficient (W) determined in step S221... q W p ), to target energy value E target It is decomposed into two parts: the energy share E allocated to reactive power regulation resources. target_q = W q E target And the energy share E allocated to active power regulation resources target_p = W p E target Subsequently, these energy shares need to be converted into corresponding power commands. For reactive power regulation resources, the reactive power reference value (Q) ref The calculation of energy share E needs to consider the dynamic response characteristics of the equipment and the voltage-reactive power sensitivity of the node. target_q The effective time constant is estimated to ensure that sufficient reactive power can be injected or absorbed to neutralize the target energy within a short period of time. For active power regulation resources (DC systems), the active power modulation reference value (ΔP) is... dc_ref The calculation of ) needs to be based on the energy share E target_p The decomposition process also includes the impact coefficients of DC system power changes on the power flow and voltage of key AC system sections, ensuring that power modulation can effectively and directionally dissipate the target energy. This decomposition process achieves a precise and coordinated mapping from system-level energy targets to device-level power commands.

[0076] Furthermore, step S221, based on the cooperative control mode, determines the target allocation weights of reactive power regulation resources and active power regulation resources for dissipated energy, including: step S2211, based on the cooperative control mode, obtaining preset initial weight benchmark values ​​for reactive power regulation resources and active power regulation resources.

[0077] The cooperative control mode has been determined in step S213, reflecting the dominant roles of the AC and DC subsystems in the current transient process. The system pre-sets corresponding initial weight reference value pairs (W) for each mode (AC-dominant, DC-dominant, and balanced cooperative). q0 W p0These benchmark values ​​are empirical parameters derived from simulation analysis, stability calculations, and operational experience summarizing from a large number of historical transient events. For example, in the "AC subsystem-dominated cooperative control mode," the initial weights might be set to (0.8, 0.2), emphasizing the core role of rapid reactive power compensation; in the "DC subsystem-dominated cooperative control mode," the initial weights might be set to (0.2, 0.8), highlighting the criticality of DC power modulation; and in the "AC / DC balanced cooperative control mode," the initial weights might be set to (0.5, 0.5), reflecting the balanced allocation of the two types of resources. These benchmark values ​​provide an initial allocation ratio that conforms to the characteristics of the mode for subsequent dynamic adjustments.

[0078] Step S2212: Obtain the dynamic reactive power reserve capacity and response speed score of key equipment in reactive power regulation resources in real time, and calculate the comprehensive availability index of reactive power regulation resources.

[0079] Key reactive power regulation equipment includes static var compensators, static synchronous compensators, and synchronous condensers located at the receiving end of the power grid or renewable energy collection points. Dynamic reactive power reserve capacity refers to the maximum incremental capacitive or inductive reactive power that these devices can provide instantaneously (or within a very short control cycle) under current operating conditions. This value is affected by the current operating point of the equipment, ambient temperature, and health status. Response speed score is a normalized index that comprehensively evaluates the measured step response time of the equipment control system, historical reliability data, and current communication status. A higher score indicates a faster and more reliable response. The overall availability index (A...) q The index is calculated by weighting and fusing the reserve capacity (after per-unit aggregation) of each key device with the average response speed score. This index quantifies the overall ability of current reactive power regulation resources to be quickly mobilized to cope with transient overvoltages.

[0080] Step S2213: In real time, obtain the modulotable active capacity and modulation rate scores of key equipment in the active power regulation resources, and calculate the comprehensive availability index of the active power regulation resources.

[0081] Key active power regulation resources mainly refer to high-voltage direct current (HVDC) transmission systems with rapid power modulation capabilities. Modular active power capacity refers to the range by which a DC system can safely increase or decrease its power output within a short period (typically on the order of hundreds of milliseconds) based on the current transmission power. This value is limited by converter station equipment margins, AC system strength, and the DC control system. The modulation rate score reflects the speed and smoothness of the DC system's execution of power increase / decrease commands, and is derived based on the dynamic performance of its control system, communication delays, and historical modulation effects. The comprehensive availability index (A...) pThe modulating capacity (normalized) is calculated by combining the modulation rate score. This index characterizes the real-time availability of the current DC system to dissipate transient energy by influencing the global power balance of the system through emergency power modulation.

[0082] Step S2214: Dynamically adjust the initial weight benchmark value based on the ratio of the comprehensive availability index of reactive power regulation resources to the comprehensive availability index of active power regulation resources.

[0083] By adapting the weight allocation to the real-time changing resource availability status, the system calculates the ratio R = A of the comprehensive availability indices for the two types of resources. q / A p Based on the magnitude of the R value, the initial weight baseline value (W) is adjusted using a preset correction function. q0 W p0 The dynamic adjustment is performed. If R is significantly greater than 1 (i.e., reactive power resources are relatively more abundant and the response is faster), W is adjusted upwards. q0 Correct W downwards p0 To make fuller use of rapid reactive power; if R is significantly less than 1, then conversely, increase the active power weight to rely on DC modulation; if R is close to 1, then maintain or fine-tune it. The correction function is usually a smooth monotonic function to avoid drastic changes in weight. This correction mechanism ensures that even in a given control mode, the final value of the weight can flexibly respond to instantaneous fluctuations in the actual availability of the equipment, avoiding issuing instructions that exceed the current capabilities of the equipment.

[0084] Step S2215: Normalize the corrected weight values ​​to obtain the target allocation weights for reactive power regulation resources and active power regulation resources.

[0085] The weight pairs (W) obtained after dynamic correction in step S2214 q’ W p’ The sum of these weights may not be 1. To meet the requirement that the sum of the weights must be 1 in subsequent energy decomposition calculations, normalization is required. The normalization calculation is: the final target allocation weight W q = W q’ / (W q’ +W p’ ), W p =W p’ / (W q’ +W p’ After this process, W q With W p This becomes a set of legitimate target allocation weights that reflect the dual impact of the current collaborative control mode and the real-time availability of resources. These weights will be directly used in the decomposition and calculation of the target energy value in step S222, thereby guiding the generation of the control quantity reference value.

[0086] Through step-by-step calculations and adjustments in steps S2211 to S2215, a dynamic weight allocation method is achieved that both follows macro-control strategies (determined by the model) and flexibly adapts to micro-resource states (determined by real-time availability). By introducing a comprehensive resource availability index and its ratio, the initial weights based on experience are corrected in real-time and online in a closed-loop manner. This ensures that the final target allocation weights not only reflect the dominant contradictions of the transient process but also incorporate the actual capacity constraints of the current execution resources. This significantly improves the rationality and adaptability of the weight allocation, as well as the feasibility and effectiveness of subsequent control commands, laying a refined decision-making foundation for the successful implementation of overall collaborative suppression control.

[0087] Further, the step S230 of decoupling the control quantity reference value and allocating it to the first stage instruction subset of the first time scale and the second stage instruction subset of the second time scale includes: step S231, identifying fast response devices and slow response devices based on the dynamic response time constants of reactive power regulation resources and active power regulation resources.

[0088] The dynamic response time constant is a physical parameter characterizing the time required for a control device to reach its target value from receiving a command, and it is a key basis for dividing control stages. In AC / DC hybrid systems, typical fast-response devices mainly refer to dynamic reactive power compensation devices based on power electronic devices, such as Static Synchronous Compensators (STATCOMs) and Static Var Compensators (SVCs). Their closed-loop response time constants are typically in the range of 10 to 50 milliseconds, enabling them to adjust reactive power output in a very short time. Slow-response devices mainly refer to the power modulation stage of high-voltage direct current transmission systems. Their time constants cover the control command calculation, communication transmission, converter valve firing angle adjustment, and DC power establishment process, typically in the range of 100 to 500 milliseconds. Based on the preset device types and their typical or measured dynamic response time constant databases, the system classifies currently available reactive and active power adjustment resources into fast-response and slow-response devices in real time, laying the foundation for subsequent staged command allocation.

[0089] Step S232: The control reference value for the fast response device is assigned to the first-stage instruction subset.

[0090] The first-stage instruction subset corresponds to the "first time scale," and its design goal is to rapidly suppress and initially stabilize transient overvoltages during the initial stage of a transient process (typically within the first few hundred milliseconds after fault clearance), utilizing the rapid adjustment capabilities of fast-response equipment. Specifically, the system directly allocates the reactive power reference values ​​calculated in step S223, targeting fast reactive power regulation resources such as STATCOM and SVC, to this instruction subset. These instructions are set to execute immediately or after a very short delay (e.g., 5-10 milliseconds). For example, when a surge in the receiving-end bus voltage is detected, the first-stage instructions will command the nearby STATCOM to immediately switch from standby mode to maximum inductive reactive power output mode to quickly absorb excess local reactive power, curb the initial voltage rise, and buy time for subsequent, more in-depth regulation, creating more stable initial conditions.

[0091] Step S233: The control reference value for the slow-response device and the correction control value added to the fast-response device to optimize the control effect are jointly allocated to the second-stage instruction subset.

[0092] The second-stage instruction subset corresponds to the "second time scale" and is executed after the first-stage actions (e.g., within a time window of 200 milliseconds to 1 second after fault clearance). This subset contains two parts: First, the active power modulation reference value for the DC transmission system calculated in step S223. This is the core control action of this stage, aiming to alleviate the power transmission bottleneck or surplus problem causing overvoltage at its root by changing the active power flow distribution over a wide range. Second, additional instructions obtained after the execution of the first-stage instructions, based on the new voltage and power measurements and the estimated system state after the DC modulation begins to have an effect, optimizing and correcting the initial output of fast-response equipment (such as STATCOM). These correction instructions aim to solve the local over-adjustment that may be caused by the first-stage actions, or to make fine-tuning to better match the DC modulation effect. Placing these two parts of instructions together in the second stage achieves precise temporal coordination between the main role of slow resources and the auxiliary optimization of fast resources.

[0093] Furthermore, step S300, which executes a set of coordinated control instructions to reduce transient electromagnetic energy and suppress transient overvoltage according to a preset timing logic, includes: step S310, sending a first-stage instruction subset to the fast-response device in the reactive power regulation resources to provide emergency reactive power support within a first time scale.

[0094] The first timescale typically refers to the initial tens to hundreds of milliseconds after fault clearance. During this critical time window, the system voltage may rise rapidly due to excess reactive power. The fast-response devices mainly include dynamic reactive power devices such as static synchronous compensators (STATCOMs) and static var compensators (SVCs). The system uses a high-speed communication network to send pre-generated reactive power reference values ​​(e.g., instructing a STATCOM to immediately output maximum inductive reactive power) from the first-stage instruction subset to their local controllers. Upon receiving the instructions, these devices, with their millisecond-level response speed, can change their reactive power output in a very short time, quickly absorbing excess reactive power near the fault point or in voltage-weak areas. This provides immediate and effective suppression of the initial rise in transient overvoltage, creating a stable initial voltage platform for subsequent, more complex coordinated control.

[0095] Step S320: After starting to execute the first stage instruction subset, send the second stage instruction subset to the slow response devices in the active power regulation resources and reactive power regulation resources, and realize the redistribution of active power and the secondary regulation of reactive power within the second time scale.

[0096] The second timescale begins after the first stage of action and typically covers the period from several hundred milliseconds to one second following the fault. After the initial voltage stabilization through rapid reactive power support in the first stage, the system immediately issues a subset of second-stage commands. This subset mainly includes two types of commands: first, active power modulation commands sent to the HVDC transmission system (such as increasing or decreasing the transmission power of specific DC lines), aiming to address the active-reactive coupling problem causing voltage issues at its root by altering the power flow distribution over a wide range; second, secondary regulation commands sent to relatively slow-responding reactive power resources (such as synchronous condensers or STATCOMs used for fine-tuning). These two types of commands work together to achieve deep readjustment of the system's global energy balance and fine-tuned control of local voltages.

[0097] Step S330: During the execution of the first-stage instruction subset and the second-stage instruction subset, the rate of change of transient electromagnetic energy level and the voltage deviation of key nodes in the AC / DC hybrid power system are monitored in real time.

[0098] To ensure the effectiveness and safety of the control process, the system performs closed-loop monitoring during control command execution. The core of the monitoring is the transient electromagnetic energy level (E0). level The rate of change of dE over time levelThe rate of change ( / dt) directly reflects the real-time rate at which coordinated control measures dissipate excess energy and is a core dynamic indicator for evaluating control effectiveness. Simultaneously, the system continuously monitors the voltage deviation (ΔV) at several predefined key nodes, typically including the AC bus of the converter station, new energy collection points, and load center buses. The voltage deviation reflects the direct achievement of the voltage target by the control actions. These two types of monitoring data together constitute the state input required by the feedback control system.

[0099] Step S340: Based on the rate of change and voltage deviation, dynamically adjust the control parameter setting value or the timing of the instruction in the second stage instruction subset.

[0100] By comparing the monitored rate of energy change with the expected value, if energy dissipation is found to be too slow, the amplitude of DC power modulation in the second-stage command may be dynamically increased. If an excessively large reverse voltage deviation is found at a critical node (such as over-adjustment leading to low voltage), the absorption command for reactive power equipment near that node may be dynamically reduced. Simultaneously, based on the uniformity of voltage recovery, the timing of command issuance to different DC lines or reactive power equipment may be fine-tuned to achieve better coordination. This dynamic adjustment ensures that the control process can adapt to the actual dynamic response of the system, avoiding over-adjustment, under-adjustment, or oscillation problems that may be caused by fixed commands.

[0101] Step S350: When the transient electromagnetic energy level drops below a preset threshold and the voltage of the critical node recovers to a preset safe range, stop executing the cooperative control instruction set.

[0102] The system presets two necessary and sufficient conditions for exiting: one is the transient electromagnetic energy level E level If the voltage remains below the threshold set by its trigger control (e.g., falling below 80% of the threshold), it indicates that the root cause of the overvoltage's excess energy has been largely dissipated. Secondly, the voltages of all monitored critical nodes have recovered and stabilized within safe operating ranges (e.g., per-unit values ​​between 0.95 and 1.05). Only when both conditions are met simultaneously does the system determine that the transient overvoltage threat has been eliminated and the control objective has been achieved. Subsequently, the system issues a command to have all mobilized regulatory resources exit emergency control mode and return to normal automatic regulation or operation according to the new steady-state setpoint, thus completing the entire closed-loop process of this coordinated suppression control.

[0103] Through a closed-loop execution process comprised of steps S310 to S350, this invention achieves complete and intelligent control for transient overvoltage collaborative suppression, progressing from "rapid triggering" to "layered execution," then to "dynamic optimization," and finally to "safe exit." This method not only emphasizes a phased, multi-resource collaborative action timing strategy but also introduces real-time feedback and dynamic adjustment based on transient energy change rate and node voltage deviation, enabling the entire control process to possess adaptability, robustness, and accuracy. This ensures that in complex AC / DC transient processes, the system can stabilize the voltage at a safe level with minimal control cost and maximum speed, and smoothly exit the emergency state, significantly improving the transient voltage safety defense capability of AC / DC hybrid power grids.

[0104] Accordingly, a second aspect of the present invention provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the above-described AC / DC hybrid power system transient overvoltage collaborative suppression control method.

[0105] Accordingly, a third aspect of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described AC / DC hybrid power system transient overvoltage collaborative suppression control method.

[0106] This invention aims to protect a method for coordinated suppression of transient overvoltage in AC / DC hybrid power systems, which has the following effects: 1. By expanding the control dimension of transient overvoltage suppression from the traditional single reactive power regulation to multi-objective coordinated scheduling of reactive and active resources based on real-time observation of system transient electromagnetic energy, and establishing a complete control closed loop from "energy observation - path planning - timing execution", it realizes the active and multi-channel dissipation and channeling of excess energy in the system after a fault; it not only effectively suppresses the rise in voltage amplitude, but also improves the transient stability limit of the system from the root of energy balance, solving the problem that the suppression effect of existing methods is limited due to the single control objective and failure to perform global optimization at the system energy level; 2. By calculating and dynamically quantifying the energy interaction intensity (dynamic coupling degree) between AC and DC subsystems in real time, and using this as the core criterion to dynamically determine the comprehensive weight of the collaborative control mode and the energy of each component, the control strategy can automatically adapt to the inherent coupling characteristics of the system under different fault scenarios and operating conditions. This significantly enhances the adaptability and accuracy of the control strategy, and solves the problems of control command mismatch, poor response effect, and even negative interaction caused by neglecting or simplifying the dynamic coupling relationship between AC and DC in existing methods. 3. By constructing a hierarchical collaborative execution architecture that "determines the target allocation weight based on the operating state, decouples it into multi-timescale commands according to the equipment response speed, and dynamically fine-tunes it based on real-time feedback during execution," this method achieves the organic unity of rapid emergency support and slow fine-tuning, as well as online safety verification and closed-loop correction of control commands. This greatly improves the dynamic response speed, overall coordination, and operational reliability of the control system, and solves the problems of rigid control timing, uncoordinated equipment response, and potential safety hazards of exceeding limits in traditional methods.

[0107] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0108] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0109] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0110] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for coordinated suppression and control of transient overvoltage in an AC / DC hybrid power system, characterized in that, The process includes the following steps: Step S100, based on the electrical quantity data collected in real time during the fault of the AC / DC hybrid power system, the transient electromagnetic energy level of the system is determined. The transient electromagnetic energy level is used to quantify the scalar or function value of the excess electromagnetic energy in the AC / DC hybrid power system after the fault; Step S200, in response to the transient electromagnetic energy level exceeding a preset threshold, with minimizing the transient electromagnetic energy level as the optimization objective, a coordinated control instruction set is generated online. The coordinated control instruction set includes a first type of instruction for scheduling reactive power regulation resources and a second type of instruction for scheduling active power regulation resources. The active power regulation resources include at least a DC transmission system capable of emergency power modulation; Step S300, according to a preset timing logic, the coordinated control instruction set is executed to reduce the transient electromagnetic energy and suppress transient overvoltage.

2. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 1, characterized in that, The method for determining the transient electromagnetic energy level of the AC / DC hybrid power system based on real-time collected electrical quantity data during a fault includes: calculating the transient electromagnetic energy of the AC subsystem after fault clearance based on real-time collected AC bus voltage and current data, as the first component energy; calculating the transient electromagnetic energy of the DC subsystem during the fault based on real-time collected DC line voltage and current data, as the second component energy; calculating the dynamic coupling degree, which characterizes the energy interaction intensity between the AC and DC subsystems, in real-time according to the operating status and interactive power data of the converter station in the AC / DC hybrid power system; and determining the transient electromagnetic energy level of the system through weighted comprehensive calculation based on the dynamic coupling degree, the first component energy, and the second component energy; wherein, in the weighted comprehensive calculation, the weight coefficients of the first component energy and the second component energy are dynamically adjusted by the dynamic coupling degree.

3. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 2, characterized in that, The step of calculating the dynamic coupling degree, which characterizes the energy interaction intensity between the AC subsystem and the DC subsystem, in real time based on the operating status and interactive power data of the converter station in the AC / DC hybrid power system includes: acquiring the interactive power of the converter station at the current sampling time and the previous sampling time, where the interactive power is the active power value of the AC / DC energy exchange intensity transmitted through the converter station, and calculating the real-time rate of change of the interactive power; acquiring the values ​​of the first component energy and the second component energy at the current sampling time and the previous sampling time, and calculating the real-time rate of change of the first component energy and the second component energy respectively; calculating the ratio of the real-time rate of change of the interactive power to the sum of the real-time rate of change of the first component energy and the real-time rate of change of the second component energy to obtain a dynamic coupling degree benchmark value; and normalizing the benchmark value of the dynamic coupling degree to obtain the dynamic coupling degree characterizing the energy interaction intensity.

4. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 2, characterized in that, The step of determining the transient electromagnetic energy level of the system based on the dynamic coupling degree, the first component energy, and the second component energy through weighted comprehensive calculation includes: determining the dominant relationship between the first component energy and the second component energy in the comprehensive calculation according to the numerical range of the dynamic coupling degree, wherein the dominant relationship includes AC dominance, DC dominance, and balanced dominance; obtaining a first weighting coefficient of the first component energy and a second weighting coefficient of the second component energy corresponding to the current dynamic coupling degree through a preset weight mapping relationship according to the dominant relationship; weighting the first component energy using the first weighting coefficient to obtain a first weighted energy, and weighting the second component energy using the second weighting coefficient to obtain a second weighted energy; obtaining a weighted comprehensive energy value from the sum of the first weighted energy and the second weighted energy; and obtaining the transient electromagnetic energy level of the system from the weighted comprehensive energy value based on a preset energy level conversion function.

5. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 2, characterized in that, The method, in response to the transient electromagnetic energy level exceeding a preset threshold, aims to minimize the transient electromagnetic energy level and generate a coordinated control instruction set online. This includes: determining the current coordinated control mode of the AC / DC hybrid power system based on the dynamic coupling degree; calculating reference values ​​for the control quantities of the reactive power regulation resources and the active power regulation resources based on the coordinated control mode and the ratio of the first component energy to the second component energy; decoupling the reference values ​​of the control quantities and allocating them to a first-stage instruction subset at a first time scale and a second-stage instruction subset at a second time scale, based on the dynamic response time constants of the reactive power regulation resources and the active power regulation resources; and combining and modifying the first-stage instruction subset and the second-stage instruction subset to generate the coordinated control instruction set, while satisfying the voltage safety constraints and equipment overload constraints of the key nodes of the AC / DC hybrid power system.

6. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 5, characterized in that, The step of determining the current cooperative control mode of the AC / DC hybrid power system based on the dynamic coupling degree includes: acquiring the values ​​of the dynamic coupling degree at the current sampling time and the previous sampling time, and calculating the real-time rate of change of the dynamic coupling degree; weighting and fusing the value of the dynamic coupling degree with its real-time rate of change to calculate the cooperative control dominance index; and mapping the cooperative control dominance index to the corresponding cooperative control mode according to a preset threshold range, wherein the first threshold range corresponds to the cooperative control mode dominated by the AC subsystem, the second threshold range corresponds to the cooperative control mode dominated by the DC subsystem, and the third threshold range corresponds to the AC / DC balanced cooperative control mode.

7. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 5, characterized in that, The step of calculating the control quantity reference values ​​of the reactive power regulation resource and the active power regulation resource based on the cooperative control mode and the ratio of the first component energy to the second component energy includes: determining the target allocation weights of the reactive power regulation resource and the active power regulation resource for dissipated energy based on the cooperative control mode; calculating the target energy value that needs to be dissipated jointly by the reactive power regulation resource and the active power regulation resource according to the ratio of the first component energy to the second component energy; and decomposing the target energy value into a reactive power reference value of the reactive power regulation resource and an active power modulation reference value of the active power regulation resource according to the target allocation weights.

8. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 7, characterized in that, The step of determining the target allocation weights of the reactive power regulation resources and the active power regulation resources for dissipated energy based on the cooperative control mode includes: obtaining preset initial weight benchmark values ​​for the reactive power regulation resources and the active power regulation resources based on the cooperative control mode; obtaining in real time the dynamic reactive power reserve capacity and response speed scores of key equipment in the reactive power regulation resources, and calculating the comprehensive availability index of the reactive power regulation resources; obtaining in real time the moduloable active power capacity and modulation rate scores of key equipment in the active power regulation resources, and calculating the comprehensive availability index of the active power regulation resources; dynamically correcting the initial weight benchmark values ​​according to the ratio of the comprehensive availability index of the reactive power regulation resources to the comprehensive availability index of the active power regulation resources; and normalizing the corrected weight values ​​to obtain the target allocation weights of the reactive power regulation resources and the active power regulation resources.

9. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 5, characterized in that, The step of decoupling and allocating the control reference value to a first-stage instruction subset at a first time scale and a second-stage instruction subset at a second time scale includes: identifying fast-response devices and slow-response devices based on the dynamic response time constants of the reactive power regulation resources and the active power regulation resources; allocating the control reference value for the fast-response devices to the first-stage instruction subset; and allocating the control reference value for the slow-response devices, as well as the corrective control value added to the fast-response devices to optimize the control effect, to the second-stage instruction subset.

10. The AC / DC hybrid power system transient overvoltage collaborative suppression control method according to claim 5, characterized in that, The step of executing the coordinated control instruction set according to a preset timing logic to reduce the transient electromagnetic energy and suppress transient overvoltage includes: sending a first-stage instruction subset to the fast-response devices in the reactive power regulation resources to provide emergency reactive power support within the first time scale; after starting the execution of the first-stage instruction subset, sending a second-stage instruction subset to the active power regulation resources and the slow-response devices in the reactive power regulation resources to achieve active power redistribution and secondary reactive power regulation within the second time scale; during the execution of the first-stage instruction subset and the second-stage instruction subset, monitoring in real time the rate of change of the transient electromagnetic energy level and the voltage deviation of key nodes in the AC / DC hybrid power system; dynamically adjusting the control parameter setting values ​​or issuance timing of the instructions in the second-stage instruction subset according to the rate of change and the voltage deviation; and stopping the execution of the coordinated control instruction set when the transient electromagnetic energy level drops below the preset threshold and the voltage of the key node recovers to the preset safe range.

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