A new energy power grid synchronous phase modifier configuration cooperative setting method and system

Abstract

The application discloses a new energy power grid synchronous compensator configuration cooperative setting method and system, first, the initial candidate node is screened out by calculating multiple indexes of each bus and a preset threshold value, and the target node is determined according to the weighted comprehensive score of multiple index values of the initial candidate node; the main support demand capacity of the target node is determined based on the short-circuit capacity improvement demand, the dynamic reactive power support demand and the voltage recovery demand after failure of the target node, the total configuration capacity of the synchronous compensator to be configured is determined by combining the basic reactive power output borne by the synchronous compensator during steady-state operation, and the accurate matching is realized by adopting different correction strategies such as correction of the target node, capacity correction, reference value adjustment or access scheme modification for different situations not meeting the preset checking index. Three-level serial checking is adopted, and correction is made if not meeting, so that invalid iteration is reduced. The cooperative strategy and the access scheme are uniformly optimized, the multi-dimensional checking synchronous meeting is ensured, and systematic joint setting is realized.

Description

Technical Field

[0001] This invention relates to the field of power systems and their automation technology, specifically to a method for configuring and setting synchronous condensers in a high-proportion renewable energy power grid. Background Technology

[0002] With the large-scale grid connection of new energy sources and the increasing proportion of power electronic equipment, the new power system exhibits characteristics of high proportion of new energy sources, high proportion of power electronic equipment, and high uncertainty in operation. As the operating rate of traditional synchronous power sources declines, the equivalent inertia and short-circuit capacity of the power grid decrease, the voltage support capacity in weak grid areas becomes insufficient, voltage recovery after faults becomes difficult, and the demand for dynamic reactive power support increases significantly.

[0003] In existing engineering projects, reactive power compensation devices such as synchronous condensers, SVG (Static Var Generator), STATCOM (Static Synchronous Compensator), SVC (Static Var Compensator), capacitors, and reactors are commonly used in combination for reactive power voltage support. Among these, synchronous condensers can provide short-circuit capacity, inertia, and dynamic reactive power support; power electronic reactive power devices such as SVG and STATCOM are characterized by fast response speed and flexible adjustment; and capacitors and reactors are mainly suitable for steady-state reactive power compensation. Different reactive power voltage support devices vary in response speed, dynamic support capability, short-circuit capacity contribution, and steady-state regulation capability.

[0004] The connection of a synchronous condenser requires corresponding primary equipment, including step-up transformers, circuit breakers, disconnect switches, current-limiting reactors, and busbars. The selection of primary equipment (such as transformer short-circuit impedance, circuit breaker breaking capacity, and current-limiting reactor parameters) directly affects the reactive power output efficiency of the synchronous condenser and the system short-circuit current level. In existing technologies, the configuration of primary equipment is usually independent of the control strategy setting of the synchronous condenser, lacking joint verification and coordinated correction for safety risks such as short-circuit current exceeding limits.

[0005] While there are existing engineering practices involving the combined application of synchronous condensers (SCDCs) with reactive power devices such as SVG, STATCOM, and SVC, the connection location, configuration capacity, functional division of labor, and control parameter tuning of SCDCs still largely rely on engineering experience. Existing methods for the connection location and configuration capacity of SCDCs typically focus on single indicators such as short-circuit capacity, reactive power deficit, or voltage deviation, lacking a comprehensive consideration of multiple indicators such as short-circuit capacity improvement, dynamic reactive power support, post-fault voltage recovery, and dynamic reactive power reserve. However, the voltage support problem in weak grid areas of new power systems is complex, and a single indicator cannot simultaneously address the differentiated needs for reactive power and voltage support at different stages of system operation, including steady-state operation, small disturbances, fault disturbances, and fault recovery.

[0006] Furthermore, since the system's demand for reactive power and voltage support varies significantly at different stages, it is also necessary to adjust the control strategies between synchronous condensers and dynamic reactive power compensation devices (SVG, STATCOM, SVC, capacitor banks, reactor banks, or reactive power control devices at new energy power plants) at different stages to achieve stable operation of the new power grid at different stages.

[0007] Furthermore, existing technologies lack simulation verification at multiple time scales and iterative correction mechanisms for the access location and capacity configuration of synchronous condensers, making it difficult to perform closed-loop optimization verification of the site selection and capacity determination results and control strategies.

[0008] Therefore, there is an urgent need to propose a method and system for the coordinated setting of synchronous condensers in new energy power grids, in order to overcome the shortcomings of existing technologies such as single location and capacity setting indicators, lack of segmented control strategies, insufficient coordination between primary equipment selection and control strategies, and insufficient simulation correction mechanisms. This will enable the optimization of the access location, capacity configuration, multiple reactive power compensation devices, and coordinated control strategies for primary equipment access of synchronous condensers. Summary of the Invention

[0009] The purpose of this invention is to address the problem that in the prior art, the selection of access nodes and the configuration of synchronous condensers are usually determined by a single indicator, which does not fully consider the complex requirements of voltage support in the new energy power grid. At the same time, the parameter settings of synchronous condensers often ignore the differences in different operating stages of the power grid and lack a coordination mechanism with other reactive power compensation devices in the power grid, making it difficult to achieve reactive power and voltage coordinated optimization of the system under different operating conditions.

[0010] To solve the above technical problems, the technical solution of the present invention is: a method for coordinating the configuration and setting of synchronous condensers in a new energy power grid, applied in a new energy power grid to coordinate with reactive power compensation devices for reactive power voltage support, comprising:

[0011] S1. Obtain the target power grid operation data, calculate the short-circuit ratio, voltage deviation, new energy access ratio, dynamic reactive power gap and voltage recovery time of each node in the power grid, construct an evaluation index system to comprehensively score each node, and select the node with the highest comprehensive score as the target node for accessing the synchronous condenser.

[0012] S2. Based on the operating data, calculate the main support capacity of the target node and the basic reactive power output undertaken by the synchronous condenser during steady-state operation, and calculate the total configuration capacity of the synchronous condenser based on the two.

[0013] S3. Based on the different operating states of the target power grid, set the reactive power reference value of the synchronous condenser and the reactive power coordination strategy between the synchronous condenser and the reactive power compensation device;

[0014] S4. Based on the output results of S1-S3 above, determine the primary equipment access scheme, and perform steady-state power flow and short-circuit capacity verification, electromechanical transient simulation verification, and electromagnetic transient simulation verification for different operating states in sequence;

[0015] S5. When any verification result does not meet the preset verification indicators, the access target node, total configuration capacity, reactive power reference value, primary equipment access scheme and reactive power coordination strategy of the synchronous condenser shall be adjusted according to the type of verification indicator that is not met, and the verification shall be re-verified until all are met.

[0016] Furthermore, the target node with the highest score for accessing the synchronous camera is selected, specifically:

[0017] S11. Obtain target power grid operation data and calculate the initial candidate index values ​​for each bus; the initial candidate indexes include short-circuit ratio, short-circuit capacity margin, voltage deviation, voltage margin, dynamic reactive power gap, new energy access capacity and proportion, electrical distance to UHVDC converter station and voltage recovery time after fault;

[0018] S12. Based on the comparison between the initial candidate index values ​​of each busbar and the corresponding preset threshold values ​​of the initial candidate index, select the busbars that meet any of the following selection conditions as the initial candidate access nodes of the synchronous condenser, and construct the initial candidate node set; the selection conditions include insufficient short-circuit ratio, weak voltage support, large dynamic reactive power gap, new energy aggregation, electrical distance from the UHVDC converter station, and insufficient voltage recovery capability after a fault.

[0019] S13. Calculate the short-circuit ratio, voltage deviation, renewable energy access ratio, dynamic reactive power gap and voltage recovery time of each candidate node in the initial candidate node set;

[0020] S14. Construct an evaluation index system to comprehensively score each candidate access node, and select the node with the highest comprehensive score as the target node for accessing the synchronous condenser.

[0021] The evaluation index system includes short-circuit capacity weakness index, voltage weakness index, dynamic reactive power gap index, new energy access ratio index, and post-fault voltage recovery index.

[0022] Furthermore, the target power grid operation data includes power grid topology, line and transformer parameters, renewable energy access capacity, reactive power compensation device parameters, bus voltage, power flow at key sections, operating mode and fault scenario data;

[0023] The bus short-circuit ratio, short-circuit capacity margin, voltage deviation, voltage margin, dynamic reactive power gap, and voltage recovery time after a fault are obtained by calculation or simulation based on the target power grid operation data.

[0024] In step S12, the judgment condition for insufficient short-circuit ratio is: the bus short-circuit ratio is less than the preset bus short-circuit ratio threshold or the bus short-circuit capacity margin is less than 0.

[0025] The criteria for determining weak voltage support are: the bus voltage deviation is greater than the preset bus voltage deviation threshold, or the bus voltage margin is less than the preset bus voltage margin threshold.

[0026] The condition for judging a large dynamic reactive power gap is: the dynamic reactive power gap of the bus is greater than the preset dynamic reactive power gap of the bus.

[0027] The criteria for determining the aggregation of new energy sources are: the proportion of new energy connected to the busbar is greater than the preset threshold for the proportion of new energy connected to the busbar.

[0028] The criteria for determining the proximity of UHVDC converter stations are: the electrical distance between the busbar and the UHVDC converter station is less than the preset busbar electrical distance threshold.

[0029] The criterion for judging insufficient voltage recovery capability after a fault is: the voltage recovery time after a bus fault is greater than the preset bus recovery time threshold.

[0030] Furthermore, in step S14, a comprehensive score is given to each candidate access node:

[0031]

[0032] Where F is the overall score of candidate node i; Short-circuit capacity weakness index; As a weak voltage indicator; This is a dynamic reactive power deficit indicator. For the intensity of new energy access; This is an indicator of voltage recovery after a fault. The weighting coefficient for the short-circuit capacity weakness index; The weighting coefficient for the voltage weakness index; The weighting coefficient for the dynamic reactive power deficit index; The weighting coefficient for the renewable energy access intensity index; The weighting coefficients for the voltage recovery index after a fault;

[0033] The calculation of the short-circuit capacity weakness index is as follows:

[0034]

[0035] in, Let i be the short-circuit ratio of the candidate access node i. This is the preset short-circuit ratio threshold;

[0036] The voltage weakness index is calculated as follows:

[0037]

[0038] in, The actual voltage of candidate access node i; This is the voltage reference value; This is the preset allowable voltage deviation;

[0039] The dynamic reactive power gap index is calculated as follows:

[0040]

[0041] in, The duration of the fault; The dynamic reactive power demand of candidate access node i at time t; The dynamic reactive power that can be provided by the reactive power compensation device of candidate access node i at time t; This represents a dynamic reactive power gap. This represents the maximum dynamic reactive power demand under fault scenarios.

[0042] The renewable energy access ratio index is used to characterize the proportion of renewable energy access scale in the region associated with a candidate access node to the total power supply and load scale of that region. Its calculation formula is:

[0043]

[0044] in, The renewable energy access capacity of the region associated with candidate access node i. Associating candidate access node i with the regional load level;

[0045] The post-fault voltage recovery index is used to characterize the extent to which the voltage recovery time of a candidate access node exceeds a preset recovery time threshold after a fault. Its calculation formula is as follows:

[0046]

[0047] in, The time required for the voltage of candidate access node i to recover to the preset operating range after the fault is cleared. This is the preset recovery time threshold.

[0048] Furthermore, the preset verification indicators in step S5 include:

[0049] The short-circuit ratio of the target node is greater than or equal to the preset short-circuit ratio threshold;

[0050] The target node's minimum voltage under fault scenarios is greater than or equal to the preset minimum fault voltage threshold.

[0051] The voltage recovery time after a fault is less than or equal to the preset recovery time threshold.

[0052] The transient overvoltage after the fault is less than or equal to the preset transient overvoltage threshold.

[0053] During the steady-state operation of a synchronous condenser, the real-time remaining dynamic reactive power reserve is greater than or equal to the dynamic reactive power reserve threshold.

[0054] The number of times each reactive power compensation device triggers its capacity limit is less than its respective preset threshold.

[0055] The maximum short-circuit current of the target node under the preset fault scenario is less than or equal to the allowable short-circuit current of the primary equipment; the allowable short-circuit current of the primary equipment is the minimum value among the rated short-circuit breaking current of the circuit breaker, the short-time withstand current of the bus, the allowable short-circuit current of the transformer, and the allowable short-circuit current of the current-limiting reactor.

[0056] Adjustments will be made according to the preset correction rules, including: the target node for synchronous condenser access, total configuration capacity, reactive power reference value, primary equipment access scheme, and reactive power coordination strategy, specifically:

[0057] 1) When the short-circuit ratio of the target node is lower than the short-circuit ratio threshold, calculate the short-circuit capacity required to meet the target short-circuit ratio requirement, and increase the total configuration capacity of the synchronous condenser accordingly; if the total configuration capacity correction is not feasible, perform incremental simulation on each candidate access node in the initial candidate access node set, calculate the short-circuit capacity improvement sensitivity, voltage support sensitivity, and post-fault voltage recovery improvement sensitivity of each candidate node, and correct the scoring and ranking accordingly, and redetermine the access target node within the initial candidate access node set;

[0058] 2) When the minimum voltage of the target node in the fault scenario is lower than the minimum fault voltage threshold, the required increase in dynamic reactive power support capacity is calculated based on the voltage support sensitivity obtained from incremental simulation, and the total configuration capacity of the synchronous condenser is corrected.

[0059] 3) When the transient overvoltage of the target node during the fault recovery phase is higher than the transient overvoltage threshold, reduce the reactive power sharing of the synchronous condenser during the fault recovery phase, and redistribute the reduction according to the proportion of available reactive power margin of the other reactive power compensation devices.

[0060] 4) When the real-time remaining dynamic reactive power reserve of the synchronous condenser is lower than the dynamic reactive power reserve threshold during the steady-state operation phase, the reactive power sharing of the synchronous condenser during the steady-state operation phase shall be reduced, and the reduced reactive power sharing shall be taken over by the other reactive power compensation devices in proportion to the available reactive power margin.

[0061] 5) When the voltage recovery time after a fault exceeds the preset recovery time threshold, the following correction shall be performed:

[0062] AS1. Calculate the voltage recovery time exceeding the limit after the fault based on the voltage recovery time and the preset recovery time threshold.

[0063] AS2. Based on the over-limit, extend the exit time of the synchronous condenser fault recovery stage, calculate the new fault recovery slope, and perform verification. If the voltage recovery time after the fault is greater than the preset recovery time threshold, proceed to step AS3; otherwise, stop the correction.

[0064] AS3. Calculate the remaining reactive power support required during the fault recovery phase based on the improved voltage recovery sensitivity obtained from the new fault slope simulation. If the total available reactive power margin of the reactive power compensation devices participating in the reactive power support during the fault recovery phase is sufficient to meet the remaining reactive power support required, then step AS4 is executed. If it is sufficient, the available reactive power margin ratio of each reactive power compensation device participating in the reactive power support during the fault recovery phase is reallocated and verified. If the voltage recovery time after the fault is still greater than the preset recovery time threshold, then step AS5 is executed. If it is not greater than the preset recovery time threshold, then the correction is stopped.

[0065] AS4. Based on the new fault slope simulation, the voltage recovery improves sensitivity and corrects the total configuration capacity of the synchronous condenser.

[0066] AS5. Based on the simulation of the available reactive power margin ratio of each reactive power compensation device participating in the reactive power support during the fault recovery phase, the voltage recovery improvement sensitivity is corrected, and the total configuration capacity of the synchronous condenser is adjusted.

[0067] 6) When any reactive power compensation device in the target power grid triggers the capacity limit more times under a preset fault scenario than a preset threshold, the reactive power compensation device that triggers the capacity limit is identified, the reactive power sharing coefficient of the device is reduced, and the reduced sharing amount is redistributed according to the available margin ratio of the other reactive power compensation devices with available reactive power margin.

[0068] 7) When the maximum short-circuit current of the target node is greater than the allowable short-circuit current of the primary equipment, the primary equipment access scheme shall be modified; if the modification still does not meet the requirements, the target node shall be reselected from the initial candidate access node set.

[0069] Further, in step S2, the total configuration capacity of the synchronous condenser is calculated as follows:

[0070] The target node is mainly supported by the required capacity. :

[0071]

[0072] Short-circuit capacity increase demand capacity :

[0073]

[0074]

[0075] in, The short-circuit capacity required for the target node m to meet the target short-circuit ratio requirement; The current short-circuit capacity of the target node m; This is the preset short-circuit ratio threshold; The target node m is associated with the renewable energy access capacity of the region. The factor that increases the short-circuit capacity of the target node by the unit synchronous condenser capacity;

[0076] Dynamic reactive power support capacity :

[0077]

[0078] in, The fault duration range for the preset fault scenario; The dynamic reactive power requirement required to maintain voltage support for target node m within the fault duration range of a preset fault scenario; The dynamic reactive power available at time t is the reactive power compensation device. The effective coefficient of dynamic reactive power support for synchronous condensers;

[0079] Capacity required for voltage restoration after a fault :

[0080]

[0081] in, The time required for the voltage of target node m to recover to the preset operating range after the preset fault scenario is cleared; The preset voltage recovery time threshold after a fault. The coefficient for improving voltage recovery time after a fault is the unit synchronous condenser capacity.

[0082] Total configuration capacity of synchronous synchrotron for:

[0083]

[0084] in, This refers to the engineering margin coefficient. The configuration capacity of the synchronous condenser required for dynamic reactive power reserve constraints;

[0085]

[0086] in, This is the basic reactive power output that the synchronous condenser undertakes during steady-state operation. The dynamic reactive power reserve ratio.

[0087] Furthermore, the different operating states include steady-state operation, small-disturbance operation, fault disturbance operation, and fault recovery operation; the reactive power reference value of the synchronous condenser is set according to each different operating state, specifically as follows:

[0088] During steady-state operation, the reactive power reference value of the synchronous condenser is set to the steady-state reactive power reference value. It is determined according to the following formula:

[0089]

[0090] in, The camera is rated to have no power for synchronization. The dynamic reactive power reserve ratio;

[0091] During the small disturbance operation phase, the reference value for the reactive power of the synchronous condenser is [value missing]. ;

[0092] in, This is the reactive power voltage regulation coefficient; Let m be the actual voltage at the target node. This is the voltage reference value;

[0093]

[0094] in, The preset first voltage deviation threshold; The preset second voltage deviation threshold; The preset reactive power output limit;

[0095] During the fault disturbance phase, the reactive power reference value of the synchronous condenser is set to the preset reactive power output limit Qlim;

[0096] During the fault recovery phase, the synchronous condenser follows the preset recovery slope. The reactive power reference value at the moment of fault clearance is gradually restored to the steady-state reactive power reference value. ;

[0097]

[0098] in, This is a reference value for reactive power at the moment the fault is cleared. This is the preset time for the synchronous condenser to exit the large reactive power support state after the fault is cleared.

[0099] Furthermore, the reactive power coordination strategy between the synchronous condenser and the reactive power compensation device is as follows:

[0100] During steady-state operation, the synchronous condenser operates according to the steady-state reactive power reference value to retain dynamic reactive power reserves, while the reactive power compensation device undertakes routine voltage regulation.

[0101] During the small disturbance operation phase, the synchronous condenser adjusts the reactive power output according to the magnitude and direction of the target node bus voltage deviation to maintain the target node bus voltage within the preset range, and the reactive power compensation device undertakes the remaining reactive power demand according to the available reactive power margin.

[0102] During the fault disturbance phase, the synchronous condenser prioritizes providing dynamic reactive power support, while the reactive power compensation device provides reactive power supplementation and participates in support for the remaining reactive power demand.

[0103] During the fault recovery phase, reduce the reactive power sharing ratio of the synchronous condenser and increase the dynamic adjustment sharing ratio of the reactive power compensation device to reduce the risk of transient overvoltage after the fault.

[0104] Furthermore, when multiple synchronous condensers are configured at the target node, the overall reactive power reference value of the synchronous condensers is first determined. Then, based on the rated reactive power capacity or available reactive power margin of each synchronous condenser, the overall reactive power reference value is allocated to each synchronous condenser. The reactive power reference value for the nth synchronous condenser is:

[0105]

[0106] in, This is the reference value for the reactive power of the nth synchronous condenser; This is a reference value for the overall reactive power of the synchronous condenser; Let n be the reactive power distribution coefficient of the nth synchronous condenser.

[0107] When synchronous condensers are initially configured, or when the real-time reactive power output status of each synchronous condenser is not available, the reactive power allocation coefficient shall be determined according to the rated reactive power capacity of each synchronous condenser.

[0108]

[0109] in, The rated non-functional capacity of the nth synchronous condenser; The number of synchronous condensers configured for the target node. This is the sum of the rated non-functional capabilities of all synchronous synchrotrons;

[0110] When the current reactive power output of each synchronous condenser is different, any synchronous condenser is close to the reactive power output limit, or dynamic reactive power reserve needs to be maintained, the reactive power allocation coefficient shall be determined according to the available reactive power margin of each synchronous condenser.

[0111] The available reactive power margin of the nth synchronous condenser is:

[0112]

[0113] The reactive power allocation factor, determined based on the available reactive power margin, is as follows:

[0114]

[0115] in, The available reactive power margin for the nth synchronous condenser; The current reactive power output of the nth synchronous condenser; This represents the total available reactive power margin for all synchronous condensers.

[0116] The present invention also provides a synchronous condenser configuration coordination system for a new energy power grid, used to execute a synchronous condenser configuration coordination method for a new energy power grid as described in any one of the claims. The system includes a data acquisition module, an access node selection module, a configuration module, and a simulation verification and iterative correction module.

[0117] The data acquisition module is used to acquire target power grid operation data, including power grid topology, line and transformer parameters, renewable energy access capacity, reactive power compensation device parameters, operation mode and fault scenario data.

[0118] The access node selection module is used to screen out the bus in the target power grid that meets the short-circuit capacity weakness index, voltage weakness index, dynamic reactive power gap index, new energy access intensity index and post-fault voltage recovery index as the initial candidate access nodes, and select the one with the highest comprehensive score as the target node for accessing the synchronous condenser.

[0119] The configuration module is used to determine the configuration capacity of the synchronous condenser, the reactive power reference value, the reactive power coordination strategy with the reactive power compensation device, and the primary equipment access scheme.

[0120] The simulation verification and iterative correction module is used to sequentially perform steady-state power flow and short-circuit capacity, electromechanical transient and electromagnetic transient simulation verification. When the verification indicators do not meet the preset requirements, the module iteratively corrects the access location, configuration capacity, reactive power reference value, primary equipment access scheme and reactive power coordination strategy of the synchronous condenser in the configuration module, and re-verifies until all verification indicators meet the requirements.

[0121] The present invention has the following beneficial effects:

[0122] This invention overcomes the limitations of traditional methods that rely solely on a single indicator such as short-circuit ratio or reactive power gap by calculating indicators such as short-circuit ratio, short-circuit capacity margin, voltage deviation, voltage margin, dynamic reactive power gap, renewable energy access capacity and proportion, electrical distance to UHVDC converter stations, and voltage recovery time after a fault for each bus. It then uses preset thresholds to screen initial candidate access nodes. Furthermore, it calculates the short-circuit ratio, voltage deviation, renewable energy access proportion, dynamic reactive power gap, and voltage recovery time for each candidate node in the initial candidate node set. A multi-indicator weighted comprehensive score is used to select target nodes from the initial candidate access nodes, ensuring that the synchronous condenser access location simultaneously considers steady-state voltage support, dynamic reactive power response, and post-fault recovery capability, adapting to the complex voltage support requirements of weak power grid areas.

[0123] This invention determines the main support capacity requirements of the target node based on the short-circuit capacity improvement requirements, dynamic reactive power support requirements, and post-fault voltage recovery requirements of the target node. Combined with the basic reactive power output undertaken by the synchronous condenser during steady-state operation, the total configuration capacity of the synchronous condenser to be configured is determined. This ensures that the synchronous condenser can support the stable operation of the power grid under various target power grid operating conditions, avoiding voltage instability caused by insufficient capacity or equipment redundancy waste caused by excessive capacity.

[0124] This invention addresses various scenarios, including insufficient short-circuit ratio, weak voltage support, large dynamic reactive power deficit, high transient overvoltage, insufficient dynamic reactive power reserve, and trigger capacity limits of reactive power compensation devices. It employs different correction strategies, such as configuration capacity adjustment, connection location adjustment, reactive power reference value adjustment, or modification of primary equipment connection schemes, achieving precise matching between correction actions and the root causes of problems. Simultaneously, it integrates a three-level serial verification mechanism—steady-state power flow and short-circuit capacity verification, electromechanical transient simulation verification, and electromagnetic transient simulation verification—to immediately halt verification and initiate correction when any step fails to meet the verification criteria, reducing the number of iterations and accelerating verification convergence. Furthermore, this invention incorporates the primary equipment connection scheme, synchronous condenser, and reactive power compensation device control strategies into a unified optimization framework, ensuring that the final scheme simultaneously meets requirements under multi-dimensional verification indicators. This achieves systematic joint tuning of synchronous condenser connection location, total configuration capacity, reactive power reference value, primary equipment connection scheme, and coordination strategy with reactive power compensation devices. Attached Figure Description

[0125] Figure 1 This is a flowchart of a method for coordinating the configuration and setting of synchronous condensers in a new energy power grid, as described in this embodiment.

[0126] Figure 2 This is a structural diagram of a synchronous condenser configuration and coordinated tuning system for a new energy power grid in this embodiment.

[0127] Figure 3This is a system configuration structure diagram of a synchronous condenser configuration and coordinated setting system for a new energy power grid in the target power grid, as described in this embodiment. Detailed Implementation

[0128] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0129] Example

[0130] like Figure 1 As shown in this embodiment, a method for coordinating the configuration and tuning of synchronous condensers in a new energy power grid is disclosed, which is applied to the new energy power grid to provide reactive power voltage support in coordination with reactive power compensation devices. Specifically, it includes the following steps:

[0131] S1. Obtain the target power grid operation data, calculate the short-circuit ratio, voltage deviation, renewable energy access ratio, dynamic reactive power gap and voltage recovery time of each node in the power grid, construct an evaluation index system to comprehensively score each node, and select the node with the highest comprehensive score as the target node for accessing the synchronous condenser.

[0132] The target power grid operation data includes power grid topology, line and transformer parameters, renewable energy access capacity, reactive power compensation device parameters, bus voltage, power flow at key sections, operating mode and fault scenario data;

[0133] The target power grid operates in several modes, including steady-state operation, small-disturbance operation, fault disturbance operation, and fault recovery operation.

[0134] The fault scenarios include high output of new energy sources, low output of new energy sources, cross-sectional power flow change scenarios, N-1 fault scenarios, short circuit fault scenarios, generator and load shedding scenarios, DC blocking scenarios, or commutation failure scenarios; among them, the N-1 fault scenario includes any single component in the line, transformer, generator set, or reactive power compensation device that is out of operation.

[0135] The short-circuit ratio, short-circuit capacity margin, voltage deviation, voltage margin, dynamic reactive power gap, minimum voltage during a fault, voltage recovery time after a fault, transient overvoltage, and sensitivity coefficient are obtained by calculation or simulation based on the target power grid operation data.

[0136] Select the target node with the highest score for access to the synchronous condenser, specifically:

[0137] S11. Obtain the target power grid operation data and calculate the initial candidate index values ​​for each bus. The initial candidate indexes include short-circuit ratio, short-circuit capacity margin, voltage deviation, voltage margin, dynamic reactive power gap, new energy access capacity and proportion, electrical distance to the UHVDC converter station, and voltage recovery time after a fault.

[0138] S12. Based on the comparison between the initial candidate index values ​​of each busbar and the corresponding preset threshold values ​​of the initial candidate index, select the busbars that meet any of the following selection conditions as the initial candidate access nodes of the synchronous condenser, and construct the initial candidate node set; the selection conditions include insufficient short-circuit ratio, weak voltage support, large dynamic reactive power gap, new energy aggregation, electrical distance from the UHVDC converter station, and insufficient voltage recovery capability after a fault.

[0139] The criteria for determining insufficient short-circuit ratio are: the bus short-circuit ratio is less than the preset bus short-circuit ratio threshold or the bus short-circuit capacity margin is less than 0.

[0140] The criteria for determining weak voltage support are: the voltage deviation between the actual bus voltage and the voltage reference value is greater than the preset bus voltage deviation threshold, or the bus voltage margin is less than the preset bus voltage margin threshold.

[0141] The condition for determining a large dynamic reactive power gap is: the dynamic reactive power gap of the bus is greater than the preset dynamic reactive power gap of the bus.

[0142] The criteria for determining the aggregation of new energy sources are: the proportion of new energy connected to the bus is greater than the preset threshold for the proportion of new energy connected to the bus.

[0143] The criteria for determining the proximity of UHVDC converter stations are: the electrical distance between the busbar and the UHVDC converter station is less than the preset busbar electrical distance threshold.

[0144] The criterion for judging insufficient voltage recovery capability after a fault is: the voltage recovery time after a bus fault is greater than the preset bus recovery time threshold.

[0145] The aforementioned preset thresholds are determined based on the target grid voltage level, operating procedures, grid connection technical requirements, equipment design parameters, historical operating data, and simulation verification results. Specifically, the preset bus short-circuit ratio threshold is set according to the bus short-circuit ratio requirements of the renewable energy access area; the preset bus voltage deviation threshold is set according to the allowable voltage deviation range of the corresponding voltage level; the preset bus voltage margin threshold is set according to the upper and lower limits of bus voltage operation and the reserved safety margin; the preset bus dynamic reactive power gap is determined based on the dynamic reactive power support requirements under preset fault scenarios and the capacity that existing reactive power compensation devices can provide; the preset bus renewable energy ratio threshold is set according to the renewable energy access scale or renewable energy penetration rate of the target area; the preset bus electrical distance threshold is determined based on the equivalent impedance between the bus and the UHVDC converter station, the electrical distance calculation results, or the converter station's near-zone division requirements; and the preset bus recovery time threshold is determined based on fault ride-through requirements, voltage recovery requirements, and electromechanical transient simulation results.

[0146] S13. Calculate the short-circuit ratio, voltage deviation, renewable energy access ratio, dynamic reactive power gap, and voltage recovery time of each candidate node in the initial candidate node set.

[0147] S14. Construct an evaluation index system to comprehensively score each candidate access node, and select the node with the highest comprehensive score as the target node for accessing the synchronous condenser.

[0148] The evaluation index system includes short-circuit capacity weakness index, voltage weakness index, dynamic reactive power gap index, new energy access ratio index, and post-fault voltage recovery index.

[0149] Overall rating:

[0150]

[0151] Where F is the overall score of candidate node i; Short-circuit capacity weakness index; As a weak voltage indicator; This is a dynamic reactive power gap indicator. For the intensity of new energy access; w1 is the weighting coefficient for the voltage recovery index after a fault; w2 is the weighting coefficient for the voltage weakness index; w3 is the weighting coefficient for the dynamic reactive power gap index; w4 is the weighting coefficient for the renewable energy access intensity index; and w5 is the weighting coefficient for the voltage recovery index after a fault.

[0152] The short-circuit capacity weakness index is used to characterize the degree to which the short-circuit ratio of a candidate access node is lower than a preset short-circuit ratio threshold. The short-circuit capacity weakness index is calculated as follows:

[0153]

[0154] in, Let i be the short-circuit ratio of the candidate access node i. The preset short-circuit ratio threshold; when Greater than or equal to hour, This indicates that candidate access node i does not have a weak short-circuit capacity; when Less than hour, It increases as the short-circuit ratio becomes more insufficient.

[0155] The preset short-circuit ratio threshold is determined based on the short-circuit ratio requirements of the target power grid's new energy access area, the weak network judgment criteria, the grid connection technology requirements, and the steady-state power flow and transient simulation verification results.

[0156] The voltage weakness index is used to characterize the degree to which the voltage deviation of a candidate access node exceeds the allowable range. The voltage weakness index is calculated as follows:

[0157]

[0158] in, The actual voltage of candidate access node i; This is the voltage reference value; This is the preset allowable voltage deviation. The voltage reference value is determined based on the rated voltage of the voltage level of the candidate access node, the target voltage value for dispatching operation, or the voltage control target of the grid connection point; the preset allowable voltage deviation is determined based on the allowable voltage deviation range, the voltage qualification interval, and the target power grid operation procedures of the voltage level of the candidate access node.

[0159] The dynamic reactive power gap index is used to characterize the extent to which dynamic reactive power demand exceeds the capacity that existing reactive power compensation devices can provide under typical fault scenarios. The dynamic reactive power gap index is calculated as follows:

[0160]

[0161] in, The duration of the fault; The dynamic reactive power demand of candidate access node i at time t; The dynamic reactive power that can be provided by the reactive power compensation device of candidate access node i at time t; This represents a dynamic reactive power gap. This represents the maximum dynamic reactive power demand under fault scenarios.

[0162] The renewable energy access intensity index is used to characterize the proportion of renewable energy access scale in the region associated with a candidate access node to the total power supply and load scale of that region. The renewable energy access intensity index is calculated as follows:

[0163]

[0164] in, The renewable energy access capacity of the region associated with candidate access node i. Associating candidate access node i with the regional load level;

[0165] The post-fault voltage recovery index is used to characterize the extent to which the voltage recovery time of a candidate access node exceeds a preset recovery time threshold after a fault. The post-fault voltage recovery index is calculated as follows:

[0166]

[0167] in, The time required for the voltage of candidate access node i to recover to the preset operating range after the fault is cleared. This is the preset recovery time threshold. The preset recovery time threshold is determined based on the target power grid fault ride-through requirements, post-fault voltage recovery assessment requirements, dispatching operation procedures, and electromechanical transient simulation verification results.

[0168] SS2. Based on operational data, calculate the main support capacity required by the target node and the basic reactive power output undertaken by the synchronous condenser during steady-state operation. Based on these two factors, calculate the total configuration capacity of the synchronous condenser, specifically:

[0169] Based on operational data, the short-circuit capacity improvement requirement, dynamic reactive power support requirement, and voltage recovery requirement of the target node under preset fault scenarios are calculated. The maximum value of the three is taken and summed with the steady-state basic reactive power calculated based on the operational data. Then, the total configuration capacity of the synchronous condenser is obtained by equivalent expansion according to the preset dynamic reactive power reserve ratio.

[0170] Short-circuit capacity increase demand capacity :

[0171]

[0172]

[0173] in, The short-circuit capacity required for the target node m to meet the target short-circuit ratio requirement; The current short-circuit capacity of the target node m; This is the preset short-circuit ratio threshold; The target node m is associated with the renewable energy access capacity of the region. The enhancement factor is the unit synchronous condenser capacity to the short-circuit capacity of the target node. The enhancement factor is determined based on the target node access location, the equivalent impedance of the synchronous condenser, the primary access scheme, and the short-circuit current calculation or incremental simulation results.

[0174] Dynamic reactive power support capacity :

[0175]

[0176] in, The fault duration interval is defined by the fault occurrence time t in the preset fault scenario. f and fault clearing time t c Sure; The dynamic reactive power requirement required to maintain voltage support for target node m within the fault duration range of a preset fault scenario; The dynamic reactive power available at time t is the reactive power compensation device. The effective coefficient of dynamic reactive power support for synchronous condensers is determined based on the rated reactive power capacity of the synchronous condenser, excitation system limitations, short-time overload capacity, response time, and transient simulation results.

[0177] Capacity required for voltage restoration after a fault :

[0178]

[0179] in, The time required for the voltage of target node m to recover to the preset operating range after the preset fault scenario is cleared; The preset voltage recovery time threshold after a fault is determined based on the target power grid fault ride-through requirements, voltage recovery assessment requirements after a fault, dispatching operation procedures, and electromechanical transient simulation verification requirements. The improvement coefficient for voltage recovery time after a fault is defined by the unit synchronous condenser capacity. The improvement coefficient is determined by incremental simulation or electromechanical transient simulation verification results based on the change in voltage recovery time after a fault at the target node before and after increasing the unit synchronous condenser capacity.

[0180]

[0181] The configuration capacity of synchronous condensers required for dynamic reactive power reserve constraints :

[0182]

[0183] in, This is the basic reactive power output that the synchronous condenser undertakes during steady-state operation. The target node primarily supports the required capacity. The dynamic reactive power reserve ratio.

[0184] Total configuration capacity of synchronous synchrotron for:

[0185]

[0186] in, Project margin coefficient; Project margin coefficient The capacity level is determined based on the equipment standard capacity level, engineering design margin, parameter uncertainties, and simulation verification results. 1. In specific engineering applications, It can be set to 1.05 to 1.20, or according to the target power grid operation procedures and equipment selection margin.

[0187] The method described in this embodiment also includes determining the number of synchronous condensers connected to the target node based on the determined total configuration capacity, wherein the number of synchronous condensers connected to the target node is one or more.

[0188] S3. Based on the different operating states of the target power grid, set the reactive power reference value for the synchronous condenser and determine the reactive power coordination strategy between the synchronous condenser and the reactive power compensation device.

[0189] Different operating states include steady-state operation, small-disturbance operation, fault disturbance operation, and fault recovery operation; the reactive power reference values ​​for the synchronous condenser are set according to different operating states, specifically as follows:

[0190] During steady-state operation, the reactive power reference value of the synchronous condenser is set to the steady-state reactive power reference value. It is determined according to the following formula:

[0191]

[0192] in, The camera is rated to have no power for synchronization. The dynamic reactive power reserve ratio.

[0193] During the small disturbance operation phase, the reference value for the reactive power of the synchronous condenser is [value missing]. ;

[0194] in, This is the reactive power voltage regulation coefficient; Let m be the actual voltage at the target node. This is the voltage reference value;

[0195]

[0196] in, The preset first voltage deviation threshold; The preset second voltage deviation threshold; The preset reactive power output limit, reactive power output limit The reactive power output limit is determined based on the synchronous condenser's rated reactive power capacity, excitation system limitations, and short-time overload capacity. The first and second voltage deviation thresholds are determined based on the allowable voltage deviation range of the target node's voltage level, voltage control dead zone, grid connection point voltage control requirements, and transient simulation verification results. The reactive power output limit is determined based on the synchronous condenser's rated reactive power capacity, excitation system limitations, stator current limitations, rotor current limitations, short-time overload capacity, and the equipment's reactive power capacity curve.

[0197] During the fault disturbance phase, the reactive power reference value of the synchronous condenser is set to the reactive power output limit. .

[0198] During the fault recovery phase, the synchronous condenser follows the preset recovery slope. The reactive power reference value at the moment of fault clearing is gradually restored to the steady-state reactive power reference value. ;

[0199]

[0200] in, The reactive power reference value of the synchronous condenser at the moment of fault clearing; The preset time is the time for the synchronous condenser to exit the large reactive power support state after the fault is cleared. The preset time is determined based on the voltage recovery requirements of the target power grid after the fault, the transient overvoltage suppression requirements, the excitation control response characteristics of the synchronous condenser, and the electromechanical transient simulation verification results.

[0201] The reactive power coordination strategy between the synchronous condenser and the dynamic reactive power compensation device is as follows:

[0202] In this embodiment, the reactive power compensation device includes SVG, STATCOM, SVC, capacitor bank, reactor bank, and reactive power control device of the inverter of the new energy power station; the parameters of the reactive power compensation device include rated reactive power capacity, maximum capacitive reactive power output, maximum inductive reactive power output, response time, reactive power adjustment slope, voltage control dead zone, upper and lower limits of reactive power output, control mode, limit triggering times, grid connection point voltage reference value, and control interface parameters with the station control system.

[0203] During steady-state operation, synchronous condensers operate according to steady-state reactive power reference values ​​to retain dynamic reactive power reserves, while reactive power compensation devices such as SVG, STATCOM, SVC, capacitor banks, reactor banks, or reactive power control devices in new energy power plants undertake routine voltage regulation.

[0204] During the small disturbance operation phase, the synchronous condenser adjusts the reactive power output according to the magnitude and direction of the target node bus voltage deviation to maintain the target node bus voltage within the preset range. Reactive power compensation devices such as SVG, STATCOM, SVC, or reactive power control devices of new energy power plants undertake the remaining reactive power demand according to their respective available reactive power margins.

[0205] The preset range is determined based on the allowable voltage deviation range of the voltage level to which the target node belongs, the scheduling operation voltage control requirements, or the grid connection point voltage control target.

[0206] The preset range can be represented as:

[0207]

[0208] in, and These are the preset lower voltage operating limit and the preset upper voltage operating limit for the target node m, respectively.

[0209] During the fault disturbance phase, synchronous condensers prioritize providing dynamic reactive power support; SVG and STATCOM provide rapid reactive power replenishment; and SVC and reactive power control devices at new energy power plants participate in support based on the remaining reactive power demand.

[0210] During the fault recovery phase, reduce the reactive power sharing ratio of synchronous condensers and increase the dynamic adjustment sharing ratio of reactive power control devices such as SVG, STATCOM, SVC, or new energy power plants to reduce the risk of transient overvoltage after a fault.

[0211] When multiple synchronous condensers are configured at the target node, first determine the overall reactive power reference value of the synchronous condensers, then determine the reactive power allocation coefficient of each synchronous condenser based on its rated reactive power capacity or available reactive power margin, and allocate the overall reactive power reference value to each synchronous condenser.

[0212] The reactive power reference value for the nth synchronous condenser is:

[0213]

[0214] in, This is the reference value for the reactive power of the nth synchronous condenser; This is a reference value for the overall reactive power of the synchronous condenser; Let be the reactive power distribution coefficient of the nth synchronous condenser.

[0215] When initially configuring synchronous condensers (SCEs), i.e., when determining the number of SCEs based on the total configuration capacity, or when the real-time reactive power output status of each SCE is not available, the reactive power distribution coefficient is determined according to the rated reactive power capacity of each SCE to achieve even distribution:

[0216]

[0217] in, The rated non-functional capacity of the nth synchronous condenser; The number of synchronous condensers configured for the target node. This is the sum of the rated power of all synchronous synchrotrons.

[0218] When the current reactive power output of each synchronous condenser is different, any synchronous condenser is close to its reactive power output limit, or a dynamic reactive power reserve needs to be maintained, the reactive power allocation coefficient shall be determined according to the available reactive power margin of each synchronous condenser.

[0219] The available reactive power margin of the nth synchronous condenser is:

[0220]

[0221] The reactive power allocation factor, determined based on the available reactive power margin, is as follows:

[0222]

[0223] in, The available reactive power margin for the nth synchronous condenser; The current reactive power output of the nth synchronous condenser; This represents the total available reactive power margin for all synchronous condensers.

[0224] S4. Based on the output results of S1-S3 above, determine the primary equipment access scheme, and perform steady-state power flow and short-circuit capacity verification, electromechanical transient simulation verification, and electromagnetic transient simulation verification for different operating states in sequence.

[0225] S5. When any verification result does not meet the preset verification indicators, adjust the access target node, total configuration capacity, reactive power reference value, primary equipment access scheme and reactive power coordination strategy of the synchronous condenser according to the type of verification indicator that is not met, and re-verify until all are met.

[0226] The preset verification indicators include:

[0227] The short-circuit ratio of the target node is greater than or equal to the preset short-circuit ratio threshold;

[0228] The target node's minimum voltage under fault scenarios is greater than or equal to the preset minimum fault voltage threshold.

[0229] The voltage recovery time after a fault is less than or equal to the preset recovery time threshold.

[0230] The transient overvoltage after the fault is less than or equal to the preset transient overvoltage threshold.

[0231] During the steady-state operation of a synchronous condenser, the real-time remaining dynamic reactive power reserve is greater than or equal to the dynamic reactive power reserve threshold.

[0232] The number of times each reactive power compensation device triggers its capacity limit is less than its respective preset threshold.

[0233] The maximum short-circuit current of the target node under the preset fault scenario is less than or equal to the allowable short-circuit current of the primary equipment; the allowable short-circuit current of the primary equipment is the minimum value among the rated short-circuit breaking current of the circuit breaker, the short-time withstand current of the bus, the allowable short-circuit current of the transformer, and the allowable short-circuit current of the current-limiting reactor.

[0234] The threshold values ​​in the above-mentioned preset verification indicators are determined based on the target power grid voltage level, grid connection technical requirements, dispatching and operation procedures, equipment design parameters, protection action requirements, and the simulation verification results of steady-state power flow, electromechanical transients, and electromagnetic transients.

[0235] The preset short-circuit ratio threshold is determined based on the short-circuit ratio requirements of the new energy access area, the weak network judgment criteria, and the grid connection technical requirements; the preset minimum fault voltage threshold is determined based on the low voltage ride-through requirements of the voltage level of the target node, the voltage support requirements during the fault, and the voltage safe operation range; the preset recovery time threshold is determined based on the voltage recovery assessment requirements after the fault, the dispatching operation procedures, and the electromechanical transient simulation results; the preset transient overvoltage threshold is determined based on the transient overvoltage allowable range of the voltage level of the target node, the equipment insulation level, and the electromagnetic transient simulation results; the preset dynamic reactive power reserve threshold is determined based on the rated reactive power capacity of the synchronous condenser, the dynamic reactive power support requirements during the fault disturbance stage, and the reserved dynamic reactive power reserve ratio; and the threshold for the number of times the capacity limit is triggered for each reactive power compensation device is determined based on the rated capacity of the reactive power compensation device, the short-time overload capacity, the control and protection action requirements, and the preset fault scenario simulation results.

[0236] The allowable short-circuit current of primary equipment is determined based on the rated short-circuit withstand capability of the relevant primary equipment at the target node, taking the minimum value among the rated short-circuit breaking current of the circuit breaker, the short-time withstand current of the bus, the allowable short-circuit current of the transformer, and the allowable short-circuit current of the current-limiting reactor.

[0237] Adjustments will be made according to the preset correction rules: the target node for synchronous condenser access, total configuration capacity, reactive power reference value, primary equipment access scheme, and reactive power coordination strategy. The specific preset correction rules are as follows:

[0238] 1) When the short-circuit ratio of the target node is lower than the short-circuit ratio threshold, the total configuration capacity of the synchronous condenser is adjusted first, the short-circuit capacity required to meet the target short-circuit ratio requirement is calculated, and the total configuration capacity of the synchronous condenser is increased accordingly; and the capacity is rounded up according to the engineering standard capacity level or multiple synchronous condensers are combined and configured.

[0239] Increase the configuration capacity of the synchronous condenser, specifically:

[0240] Calculate short-circuit capacity deficit The short-circuit capacity deficit is the difference between the short-circuit capacity required to meet the target short-circuit ratio requirement and the current short-circuit capacity of the target node.

[0241]

[0242] The improvement factor of the target node's short-circuit capacity based on the short-circuit capacity deficit and the unit synchronous condenser capacity. Calculate the required increase in synchronous condenser capacity. :

[0243]

[0244] The total configuration capacity of the improved synchronous condenser is:

[0245]

[0246] in, To increase the total configuration capacity of the synchronous condenser.

[0247] If the short-circuit ratio of the target node is still lower than the threshold after increasing the configuration capacity, or if it is not feasible to continue increasing the capacity due to access interval, site conditions, short-circuit current bearing capacity or primary equipment capacity limitations, then the access location will be re-determined within the initial candidate access node set.

[0248] When redetermining the target access node, incremental simulations are performed on each candidate access node in the initial candidate access node set: While keeping the target power grid operation mode, fault scenario, and reactive power compensation device parameters unchanged, a unit synchronous condenser capacity ΔQ is added at each candidate access node. The changes in short-circuit ratio, minimum voltage during the fault, and voltage recovery time after the fault are calculated, yielding the sensitivity to short-circuit capacity improvement. Voltage Support Sensitivity Improved sensitivity after voltage recovery following a fault Based on this, the scores are revised and ranked, and the candidate access node with the highest comprehensive score is selected as the revised access location; the revised score is determined by the following formula:

[0249]

[0250] in, E is the corrected score for candidate access node i; E is the engineering access condition evaluation value of candidate access node i. for Corresponding weighting coefficients; for Corresponding weighting coefficients; for Corresponding weighting coefficients; The weighting coefficient corresponding to E;

[0251]

[0252]

[0253]

[0254] in, Let be the short-circuit ratio of candidate access node i when the synchronous modulator capacity is Q; Increase the capacity of the synchronous condenser by one unit for candidate access node i. The short-circuit ratio after; Let V be the lowest voltage during a fault in candidate access node i when the synchronous modulator capacity is Q. To increase the capacity of the unit synchronous condenser The lowest voltage during the subsequent fault period; Let be the voltage recovery time after a fault for candidate access node i when the synchronous modulator capacity is Q. To increase the capacity of the unit synchronous condenser Voltage recovery time after a fault.

[0255] 2) The lowest voltage of the target node from the time of fault occurrence to the time of fault clearance in a fault scenario. Below the minimum fault voltage threshold At that time, the required increase in dynamic reactive power support capacity is calculated based on the voltage support sensitivity obtained from incremental simulation:

[0256]

[0257] The revised synchronous condenser configuration capacity is:

[0258]

[0259] in, For the required increase in dynamic reactive power support capacity; S U The sensitivity of the synchronous condenser capacity to the minimum voltage increase under fault scenarios is measured in units.

[0260] 3) Transient overvoltage at the target node after a fault Above the transient overvoltage threshold At the same time, reduce the reactive power sharing of the synchronous condenser during the fault recovery phase, and redistribute the reduced reactive power sharing according to the available reactive power margin of the remaining reactive power compensation devices.

[0261] The reduction in reactive power sharing factor of synchronous condensers during the fault recovery phase is:

[0262]

[0263] The corrected reactive power sharing factor for synchronous condensers is:

[0264]

[0265] in, The reduction in the reactive power sharing factor of the synchronous condenser is a proportional quantity.

[0266] The amount of reactive power reduction achieved by the synchronous condenser is:

[0267]

[0268] in, This represents the total reactive power regulation required for the target node during the fault recovery phase.

[0269] The available reactive power margin of the remaining reactive power compensation devices j participating in the redistribution for:

[0270]

[0271] The amount of reactive power sharing added by the j-th reactive power compensation device is:

[0272]

[0273] The corrected reactive power sharing factor for the j-th reactive power compensation device is:

[0274]

[0275] in, The reactive power sharing factor of the synchronous condenser before correction; This is the minimum reactive power sharing factor for the synchronous condenser; is the transient overvoltage correction factor; D is the set of reactive power compensation devices that participate in reactive power sharing and redistribution and have available reactive power margin; Let J be the available reactive power margin of the j-th reactive power compensation device; Let J be the maximum available reactive power of the j-th reactive power compensation device; The current reactive power output of the j-th reactive power compensation device; The reactive power sharing coefficient before correction for the j-th reactive power compensation device; The reactive power sharing coefficient after correction for the j-th reactive power compensation device; This is the sum of available reactive power margins for all reactive power compensation devices participating in reactive power sharing and redistribution.

[0276] 4) If the real-time dynamic reactive power reserve of the synchronous condenser is during steady-state operation... Below the dynamic reactive power reserve threshold This reduces the reactive power contribution of the synchronous condenser during steady-state operation and redistributes the reduced reactive power contribution according to the available reactive power margin of the other reactive power compensation devices.

[0277] The reactive power sharing factor of the pre-corrected synchronous condenser during steady-state operation. for:

[0278]

[0279] in, For the reactive power output during the steady-state operation of the synchronous condenser; The total reactive power regulation demand during the steady-state operation phase of the target node;

[0280] Real-time remaining dynamic reactive power reserve during steady-state operation of synchronous condensers for:

[0281]

[0282] in, The synchronous adjustment camera is rated to have no functional capacity.

[0283] when < At that time, the target value of the steady-state reactive power sharing coefficient of the synchronous condenser is determined based on the dynamic reactive power reserve threshold. :

[0284]

[0285] The corrected steady-state reactive power sharing factor for synchronous condensers is: :

[0286]

[0287] in, This is the minimum reactive power sharing factor in steady state for synchronous condensers.

[0288] Corrected steady-state reactive power output of synchronous condenser for:

[0289]

[0290] The reduction in reactive power sharing factor during the steady-state operation of a synchronous condenser for:

[0291]

[0292] The reduced steady-state reactive power sharing of synchronous condensers for:

[0293]

[0294] Or, equivalently, it can be represented as:

[0295]

[0296] The available reactive power margin of the remaining reactive power compensation devices j participating in the undertaking for:

[0297]

[0298] The steady-state reactive power load undertaken by the j-th reactive power compensation device for:

[0299]

[0300] The corrected steady-state reactive power sharing coefficient of the j-th reactive power compensation device for:

[0301]

[0302] 5) When the voltage recovery time after a fault exceeds the preset recovery time threshold, the following correction shall be performed:

[0303] AS1. Calculate the voltage recovery time exceeding the limit after the fault based on the post-fault voltage recovery time and a preset recovery time threshold. :

[0304]

[0305] in, The voltage recovery time after a fault at target node m; This is the preset voltage recovery time threshold after a fault.

[0306] AS2. Based on the over-limit, extend the exit time of the synchronous condenser fault recovery stage, calculate the new fault recovery slope, and check based on the new fault recovery slope. If the voltage recovery time after the fault is greater than the preset recovery time threshold, proceed to step AS3; otherwise, stop the correction.

[0307]

[0308] in, This refers to the time before the fault was corrected and the user exited the recovery process. This refers to the corrected fault recovery exit time; This is the recovery time correction factor.

[0309] New fault recovery slope :

[0310]

[0311] in, The reactive power reference value of the synchronous condenser at the moment of fault clearing. This is the reference value for steady-state reactive power.

[0312] AS3. Calculate the remaining reactive power support required during the fault recovery phase based on the improved voltage recovery sensitivity obtained from the new fault slope simulation. The system determines whether the total available reactive power margin of the reactive power compensation devices participating in the reactive power support during the fault recovery phase meets the remaining reactive power support amount that needs to be supplemented. If it does not meet the requirements, step AS5 is executed. If it does meet the requirements, the available reactive power margin ratio of each reactive power compensation device participating in the reactive power support during the fault recovery phase is reallocated and verified. If the voltage recovery time after the fault is still greater than the preset recovery time threshold, step AS4 is executed. If it is not greater than the preset recovery time threshold, the correction is stopped.

[0313] The remaining reactive power support that needs to be supplemented The calculation is as follows:

[0314]

[0315] in, To improve the sensitivity of voltage recovery based on simulation with a new fault slope.

[0316]

[0317] in, The amount of reactive power support added to the j-th reactive power compensation device during the fault recovery phase. D represents the amount of reactive power support that needs to be supplemented during the fault recovery phase, and D is the set of reactive power compensation devices that participate in reactive power sharing and redistribution and have available reactive power margin.

[0318] AS4. Based on the new fault slope simulation, the voltage recovery improves sensitivity and corrects the total configuration capacity of the synchronous condenser.

[0319] Calculate the required increase in synchronous condenser capacity. for:

[0320]

[0321] The post-fault voltage recovery time exceeds the limit after correction based on the new fault slope;

[0322] Corrected total configuration capacity of synchronous condenser for:

[0323]

[0324] in, The total configuration capacity of the synchronous condenser after the new fault slope correction.

[0325] AS5. Based on the simulation of the available reactive power margin ratio of each reactive power compensation device participating in the reactive power support during the fault recovery phase, the voltage recovery sensitivity is improved, and the total configuration capacity of the synchronous condenser is corrected.

[0326] Calculate the required increase in synchronous condenser capacity. for:

[0327]

[0328] The voltage recovery time after the fault exceeds the limit after being corrected based on the proportion of available reactive power margin of each reactive power compensation device participating in the reactive power support during the fault recovery phase.

[0329] The voltage recovery improvement sensitivity is obtained by simulation based on the available reactive power margin ratio of each reactive power compensation device participating in the reactive power support during the fault recovery phase.

[0330] Corrected total configuration capacity of synchronous condenser for:

[0331]

[0332] in, The total configuration capacity of the synchronous condenser is adjusted to the ratio of available reactive power margin of each reactive power compensation device participating in the reactive power support during the fault recovery phase.

[0333] 6) When any reactive power compensation device in the target power grid triggers the capacity limit more times under a preset fault scenario than the preset threshold, identify the reactive power compensation device that has exceeded the trigger capacity limit and record it as the p-th reactive power compensation device.

[0334] Number of times the capacity limit of the p-th reactive power compensation device is triggered. for:

[0335]

[0336] in, For a set of preset fault scenarios, Let be the simulation time interval corresponding to the s-th fault scenario. Let be the reactive power output of the p-th reactive power compensation device at time t under the s-th fault scenario. Let I( be the maximum available reactive power of the p-th reactive power compensation device) The parentheses are an indicator function that takes the value 1 if the condition inside the parentheses is true, and 0 otherwise.

[0337] when > When the number of triggers exceeds the capacity limit, the reactive power sharing coefficient of the p-th reactive power compensation device is reduced, and the amount of reduction in its reactive power sharing coefficient is... for:

[0338]

[0339] The corrected reactive power sharing factor for the p-th reactive power compensation device is:

[0340]

[0341] The reactive power reduction of the p-th reactive power compensation device for:

[0342]

[0343] in, This represents the total reactive power adjustment required by the target node under the current preset fault scenario.

[0344] D represents the set of reactive power compensation devices that participate in reactive power sharing and redistribution and have available reactive power margin. The available reactive power margin of the j-th reactive power compensation device is:

[0345]

[0346] The reactive power load undertaken by the j-th reactive power compensation device is:

[0347]

[0348] The corrected sharing factor for the j-th device:

[0349]

[0350] in, For the preset number of times threshold, and These are the reactive power sharing coefficients of the p-th reactive power compensation device before and after correction, respectively. Let p be the minimum reactive power sharing factor for the p-th reactive power compensation device. This is a correction coefficient for the number of times the limit is triggered. Let j be the available reactive power margin of the reactive power compensation device. This represents the reactive power share undertaken by the j-th reactive power compensation device.

[0351] 7) When the maximum short-circuit current of the target node is greater than the allowable short-circuit current of the primary equipment, the primary equipment connection scheme shall be modified first, including increasing the rated short-circuit breaking current level of the circuit breaker, increasing the short-time withstand current level of the bus, adjusting the short-circuit impedance of the step-up transformer, adding or adjusting the parameters of the current-limiting reactor, and adjusting one or more of the connection interval or primary wiring method.

[0352] If, after the primary equipment access scheme is modified, the maximum short-circuit current of the target node is still greater than the allowable short-circuit current of the primary equipment, or if the access scheme cannot be further modified due to limitations such as access interval, site conditions, or equipment selection limits, a new access location will be selected from the initial candidate access node set.

[0353] Specifically:

[0354] Incremental simulations were performed on each candidate access node in the initial candidate access node set: while keeping the target power grid operation mode, fault scenario and reactive power compensation device parameters unchanged, a unit synchronous condenser capacity was added at each candidate access node, and the changes in short-circuit ratio, minimum voltage during fault and voltage recovery time after fault were calculated. The sensitivity of short-circuit capacity improvement, voltage support sensitivity and voltage recovery improvement sensitivity after fault were obtained respectively, and the corrected scores and rankings were performed accordingly. The candidate access node with the highest comprehensive score was selected as the corrected access location.

[0355] Embodiments of the present invention also include a synchronous condenser configuration coordination system for a new energy power grid, used to execute the aforementioned synchronous condenser configuration coordination method for a new energy power grid. The system includes a data acquisition module, an access node selection module, a configuration module, and a simulation verification and iterative correction module.

[0356] The data acquisition module is used to acquire target power grid operation data, including power grid topology, line and transformer parameters, renewable energy access capacity, reactive power compensation device parameters, operation mode and fault scenario data.

[0357] The access node selection module is used to screen out the bus in the target power grid that meets the short-circuit capacity weakness index, voltage weakness index, dynamic reactive power gap index, new energy access intensity index and post-fault voltage recovery index as the initial candidate access nodes, and select the one with the highest comprehensive score as the target node for accessing the synchronous condenser.

[0358] The configuration module is used to determine the configuration capacity of the synchronous condenser, the reactive power reference value, the reactive power coordination strategy with the reactive power compensation device, and the primary equipment access scheme.

[0359] The simulation verification and iterative correction module is used to sequentially perform steady-state power flow and short-circuit capacity, electromechanical transient and electromagnetic transient simulation verification. When the verification indicators do not meet the preset requirements, the module iteratively corrects the access location, configuration capacity, reactive power reference value, primary equipment access scheme and reactive power coordination strategy of the synchronous condenser in the configuration module, and re-verifies until all verification indicators meet the requirements.

[0360] It should be noted that all candidate access nodes, target nodes, and corrected and re-determined access locations involved in this invention must meet the engineering access conditions. Engineering access conditions refer to the requirements of power grid engineering design and operation regulations for the synchronous condenser when it is connected to the target bus in actual engineering projects, including its access voltage level, number of available bays, site area and geological conditions, short-circuit current withstand capability, step-up transformer access conditions, and primary equipment access scheme. In other words, the selection of candidate nodes, the determination of target nodes, and the correction of access locations are all carried out under the premise of meeting the engineering access conditions. These engineering access conditions, as an implicit constraint on bus selection and correction in each step of this invention, run throughout the entire process of determining and setting the access location of the synchronous condenser.

[0361] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for coordinating the setting of synchronous condensers in a new energy power grid, applied in a new energy power grid to coordinate with reactive power compensation devices for reactive power voltage support, characterized in that: include: S1. Obtain the target power grid operation data, calculate the short-circuit ratio, voltage deviation, new energy access ratio, dynamic reactive power gap and voltage recovery time of each node in the power grid, construct an evaluation index system to comprehensively score each node, and select the node with the highest comprehensive score as the target node for accessing the synchronous condenser. S2. Based on the operating data, calculate the main support capacity of the target node and the basic reactive power output undertaken by the synchronous condenser during steady-state operation, and calculate the total configuration capacity of the synchronous condenser based on the two. S3. Based on the different operating states of the target power grid, set the reactive power reference value of the synchronous condenser and the reactive power coordination strategy between the synchronous condenser and the reactive power compensation device; S4. Based on the output results of S1-S3 above, determine the primary equipment access scheme, and perform steady-state power flow and short-circuit capacity verification, electromechanical transient simulation verification, and electromagnetic transient simulation verification for different operating states in sequence; S5. When any verification result does not meet the preset verification indicators, adjust the access target node, total configuration capacity, reactive power reference value, primary equipment access scheme and reactive power coordination strategy of the synchronous condenser according to the type of verification indicator that is not met, and re-verify until all are met.

2. The method for coordinated tuning of synchronous condensers in a new energy power grid according to claim 1, characterized in that: Select the target node with the highest score for access to the synchronous condenser, specifically: S11. Obtain target power grid operation data and calculate the values ​​of each initial candidate index for each bus. The initial candidate indexes include short-circuit ratio, short-circuit capacity margin, voltage deviation, voltage margin, dynamic reactive power gap, new energy access capacity and proportion, electrical distance to UHVDC converter station, and voltage recovery time after fault. S12. Based on the comparison between the initial candidate index values ​​of each busbar and the corresponding preset threshold values ​​of the initial candidate index, select the busbars that meet any of the following selection conditions as the initial candidate access nodes of the synchronous condenser, and construct the initial candidate node set; the selection conditions include insufficient short-circuit ratio, weak voltage support, large dynamic reactive power gap, new energy aggregation, electrical distance from the UHVDC converter station, and insufficient voltage recovery capability after a fault. S13. Calculate the short-circuit ratio, voltage deviation, renewable energy access ratio, dynamic reactive power gap and voltage recovery time of each candidate node in the initial candidate node set; S14. Construct an evaluation index system to comprehensively score each candidate access node, and select the node with the highest comprehensive score as the target node for accessing the synchronous condenser. The evaluation index system includes short-circuit capacity weakness index, voltage weakness index, dynamic reactive power gap index, new energy access ratio index, and post-fault voltage recovery index.

3. The method for coordinated tuning of synchronous condensers in a new energy power grid according to claim 2, characterized in that: The target power grid operation data includes power grid topology, line and transformer parameters, renewable energy access capacity, reactive power compensation device parameters, bus voltage, power flow at key sections, operating mode and fault scenario data; The bus short-circuit ratio, short-circuit capacity margin, voltage deviation, voltage margin, dynamic reactive power gap, and voltage recovery time after a fault are obtained by calculation or simulation based on the target power grid operation data. In step S12, the judgment condition for insufficient short-circuit ratio is: the bus short-circuit ratio is less than the preset bus short-circuit ratio threshold or the bus short-circuit capacity margin is less than 0. The criteria for determining weak voltage support are: the bus voltage deviation is greater than the preset bus voltage deviation threshold, or the bus voltage margin is less than the preset bus voltage margin threshold. The condition for judging a large dynamic reactive power gap is: the dynamic reactive power gap of the bus is greater than the preset dynamic reactive power gap of the bus. The criteria for determining the aggregation of new energy sources are: the proportion of new energy connected to the busbar is greater than the preset threshold for the proportion of new energy connected to the busbar. The criteria for determining the proximity of UHVDC converter stations are: the electrical distance between the busbar and the UHVDC converter station is less than the preset busbar electrical distance threshold. The criterion for judging insufficient voltage recovery capability after a fault is: the voltage recovery time after a bus fault is greater than the preset bus recovery time threshold.

4. The method for coordinated tuning of synchronous condensers in a new energy power grid according to claim 2, characterized in that: In step S14, a comprehensive score is given to each candidate access node: Where F is the overall score of candidate node i; Short-circuit capacity weakness index; As a weak voltage indicator; This is a dynamic reactive power deficit indicator. For the intensity of new energy access; w1 is the weighting coefficient for the voltage recovery index after a fault; w2 is the weighting coefficient for the voltage weakness index; w3 is the weighting coefficient for the dynamic reactive power gap index; w4 is the weighting coefficient for the renewable energy access intensity index; w5 is the weighting coefficient for the voltage recovery index after a fault. The calculation of the short-circuit capacity weakness index is as follows: in, Let i be the short-circuit ratio of the candidate access node i. This is the preset short-circuit ratio threshold; The voltage weakness index is calculated as follows: in, The actual voltage of candidate access node i; This is the voltage reference value; This is the preset allowable voltage deviation; The dynamic reactive power gap index is calculated as follows: in, The duration of the fault; The dynamic reactive power demand of candidate access node i at time t; The dynamic reactive power that can be provided by the reactive power compensation device of candidate access node i at time t; This represents a dynamic reactive power gap. This represents the maximum dynamic reactive power demand under fault scenarios. The renewable energy access ratio index is used to characterize the proportion of renewable energy access scale in the region associated with a candidate access node to the total power supply and load scale of that region. Its calculation formula is: in, The renewable energy access capacity of the region associated with candidate access node i. Associating candidate access node i with the regional load level; The post-fault voltage recovery index is used to characterize the extent to which the voltage recovery time of a candidate access node exceeds a preset recovery time threshold after a fault. Its calculation formula is as follows: in, The time required for the voltage of candidate access node i to recover to the preset operating range after the fault is cleared. This is the preset recovery time threshold.

5. The method for coordinated tuning of synchronous condensers in a new energy power grid according to claim 2, characterized in that: The preset verification indicators in step S5 include: The short-circuit ratio of the target node is greater than or equal to the preset short-circuit ratio threshold; The target node's minimum voltage under fault scenarios is greater than or equal to the preset minimum fault voltage threshold. The voltage recovery time after a fault is less than or equal to the preset recovery time threshold. The transient overvoltage after the fault is less than or equal to the preset transient overvoltage threshold. During the steady-state operation of a synchronous condenser, the real-time remaining dynamic reactive power reserve is greater than or equal to the dynamic reactive power reserve threshold. The number of times each reactive power compensation device triggers its capacity limit is less than its respective preset threshold. The maximum short-circuit current of the target node under the preset fault scenario is less than or equal to the allowable short-circuit current of the primary equipment; the allowable short-circuit current of the primary equipment is the minimum value among the rated short-circuit breaking current of the circuit breaker, the short-time withstand current of the bus, the allowable short-circuit current of the transformer, and the allowable short-circuit current of the current-limiting reactor. Adjustments will be made according to the preset correction rules, including: the target node for synchronous condenser access, total configuration capacity, reactive power reference value, primary equipment access scheme, and reactive power coordination strategy, specifically: 1) When the short-circuit ratio of the target node is lower than the short-circuit ratio threshold, calculate the short-circuit capacity required to meet the target short-circuit ratio requirement, and increase the total configuration capacity of the synchronous condenser accordingly; if the total configuration capacity correction is not feasible, perform incremental simulation on each candidate access node in the initial candidate access node set, calculate the short-circuit capacity improvement sensitivity, voltage support sensitivity, and post-fault voltage recovery improvement sensitivity of each candidate node, and correct the scoring and ranking accordingly, and redetermine the access target node within the initial candidate access node set; 2) When the minimum voltage of the target node in the fault scenario is lower than the minimum fault voltage threshold, the required increase in dynamic reactive power support capacity is calculated based on the voltage support sensitivity obtained from incremental simulation, and the total configuration capacity of the synchronous condenser is corrected. 3) When the transient overvoltage of the target node during the fault recovery phase is higher than the transient overvoltage threshold, reduce the reactive power sharing of the synchronous condenser during the fault recovery phase, and redistribute the reduction according to the proportion of available reactive power margin of the other reactive power compensation devices. 4) When the real-time remaining dynamic reactive power reserve of the synchronous condenser is lower than the dynamic reactive power reserve threshold during the steady-state operation phase, the reactive power sharing of the synchronous condenser during the steady-state operation phase shall be reduced, and the reduced reactive power sharing shall be taken over by the other reactive power compensation devices in proportion to the available reactive power margin. 5) When the voltage recovery time after a fault exceeds the preset recovery time threshold, the following correction shall be performed: AS1. Calculate the voltage recovery time exceeding the limit after the fault based on the voltage recovery time and the preset recovery time threshold. AS2. Based on the over-limit, extend the exit time of the synchronous condenser fault recovery stage, calculate the new fault recovery slope, and perform verification. If the voltage recovery time after the fault is greater than the preset recovery time threshold, proceed to step AS3; otherwise, stop the correction. AS3. Calculate the remaining reactive power support required during the fault recovery phase based on the improved voltage recovery sensitivity obtained from the new fault slope simulation. If the total available reactive power margin of the reactive power compensation devices participating in the reactive power support during the fault recovery phase is sufficient to meet the remaining reactive power support required, then step AS4 is executed. If it is sufficient, the available reactive power margin ratio of each reactive power compensation device participating in the reactive power support during the fault recovery phase is reallocated and verified. If the voltage recovery time after the fault is still greater than the preset recovery time threshold, then step AS5 is executed. If it is not greater than the preset recovery time threshold, then the correction is stopped. AS4. Based on the new fault slope simulation, the voltage recovery improves sensitivity and corrects the total configuration capacity of the synchronous condenser. AS5. Based on the simulation of the available reactive power margin ratio of each reactive power compensation device participating in the reactive power support during the fault recovery phase, the voltage recovery improvement sensitivity is corrected, and the total configuration capacity of the synchronous condenser is adjusted. 6) When any reactive power compensation device in the target power grid triggers the capacity limit more times under a preset fault scenario than a preset threshold, the reactive power compensation device that triggers the capacity limit is identified, the reactive power sharing coefficient of the device is reduced, and the reduced sharing amount is redistributed according to the available margin ratio of the other reactive power compensation devices with available reactive power margin. 7) When the maximum short-circuit current of the target node is greater than the allowable short-circuit current of the primary equipment, the primary equipment access scheme shall be modified; if the modification still does not meet the requirements, the target node shall be reselected from the initial candidate access node set.

6. The method for coordinated tuning of synchronous condensers in a new energy power grid according to claim 1, characterized in that: Step S2 calculates the total configuration capacity of the synchronous condenser, specifically as follows: The target node is mainly supported by the required capacity. : Short-circuit capacity increase demand capacity : in, The short-circuit capacity required for the target node m to meet the target short-circuit ratio requirement; The current short-circuit capacity of the target node m; This is the preset short-circuit ratio threshold; The target node m is associated with the renewable energy access capacity of the region. The factor that increases the short-circuit capacity of the target node by the unit synchronous condenser capacity; Dynamic reactive power support capacity : in, The fault duration range for the preset fault scenario; The dynamic reactive power requirement required to maintain voltage support for target node m within the fault duration range of a preset fault scenario; The dynamic reactive power available at time t is the reactive power compensation device. The effective coefficient of dynamic reactive power support for synchronous condensers; Capacity required for voltage restoration after a fault : in, The time required for the voltage of target node m to recover to the preset operating range after the preset fault scenario is cleared; The preset voltage recovery time threshold after a fault. The coefficient for improving voltage recovery time after a fault is the unit synchronous condenser capacity. Total configuration capacity of synchronous synchrotron for: in, This refers to the engineering margin coefficient; The configuration capacity of the synchronous condenser required for dynamic reactive power reserve constraints; in, This is the basic reactive power output that the synchronous condenser undertakes during steady-state operation. The dynamic reactive power reserve ratio.

7. The method for coordinated tuning of synchronous condensers in a new energy power grid according to claim 1, characterized in that: Different operating states include steady-state operation, small-disturbance operation, fault disturbance operation, and fault recovery operation; the reactive power reference values ​​for the synchronous condenser are set according to different operating states, specifically as follows: During steady-state operation, the reactive power reference value of the synchronous condenser is set to the steady-state reactive power reference value. It is determined according to the following formula: in, The camera is rated to have no power for synchronization. The dynamic reactive power reserve ratio; During the small disturbance operation phase, the reference value for the reactive power of the synchronous condenser is [value missing]. ; in, This is the reactive power voltage regulation coefficient; Let m be the actual voltage at the target node. This is the voltage reference value; in, The preset first voltage deviation threshold; The preset second voltage deviation threshold; This is the preset reactive power output limit; During the fault disturbance phase, the reactive power reference value of the synchronous condenser is set to the preset reactive power output limit Q. lim ; During the fault recovery phase, the synchronous condenser follows the preset recovery slope. The reactive power reference value at the moment of fault clearing is gradually restored to the steady-state reactive power reference value. ; in, This is a reference value for reactive power at the moment the fault is cleared. The preset time for the synchronous condenser to exit the large reactive power support state after the fault is cleared.

8. The method for coordinated tuning of synchronous condensers in a new energy power grid according to claim 7, characterized in that: The reactive power coordination strategy between the synchronous condenser and the reactive power compensation device is as follows: During steady-state operation, the synchronous condenser operates according to the steady-state reactive power reference value to retain dynamic reactive power reserves, while the reactive power compensation device undertakes routine voltage regulation. During the small disturbance operation phase, the synchronous condenser adjusts the reactive power output according to the magnitude and direction of the target node bus voltage deviation to maintain the target node bus voltage within the preset range, and the reactive power compensation device undertakes the remaining reactive power demand according to the available reactive power margin. During the fault disturbance phase, the synchronous condenser prioritizes providing dynamic reactive power support, while the reactive power compensation device provides reactive power supplementation and participates in support for the remaining reactive power demand. During the fault recovery phase, reduce the reactive power sharing ratio of the synchronous condenser and increase the dynamic adjustment sharing ratio of the reactive power compensation device to reduce the risk of transient overvoltage after the fault.

9. The method for coordinated tuning of synchronous condensers in a new energy power grid according to claim 8, characterized in that: The number of synchronous condensers connected to the target node is one or more; When multiple synchronous condensers are configured at the target node, the overall reactive power reference value of the synchronous condensers is first determined. Then, based on the rated reactive power capacity or available reactive power margin of each synchronous condenser, the overall reactive power reference value is allocated to each synchronous condenser. The reactive power reference value for the nth synchronous condenser is: in, This is the reference value for the reactive power of the nth synchronous condenser; This is a reference value for the overall reactive power of the synchronous condenser; Let n be the reactive power distribution coefficient of the nth synchronous condenser. When synchronous condensers are initially configured, or when the real-time reactive power output status of each synchronous condenser is not available, the reactive power allocation coefficient shall be determined according to the rated reactive power capacity of each synchronous condenser. in, The rated non-functional capacity of the nth synchronous condenser; The number of synchronous condensers configured for the target node. This is the sum of the rated non-functional capabilities of all synchronous synchrotrons; When the current reactive power output of each synchronous condenser is different, any synchronous condenser is close to the reactive power output limit, or it is necessary to retain dynamic reactive power reserve, the reactive power allocation coefficient shall be determined according to the available reactive power margin of each synchronous condenser. The available reactive power margin of the nth synchronous condenser is: The reactive power allocation factor, determined based on the available reactive power margin, is as follows: in, The available reactive power margin for the nth synchronous condenser; The current reactive power output of the nth synchronous condenser; This represents the total available reactive power margin for all synchronous condensers.

10. A synchronous condenser configuration coordination and tuning system for a new energy power grid, used to execute a synchronous condenser configuration coordination and tuning method for a new energy power grid as described in any one of claims 1 to 9, characterized in that: The system includes a data acquisition module, an access node selection module, a configuration module, and a simulation verification and iterative correction module. The data acquisition module is used to acquire target power grid operation data, including power grid topology, line and transformer parameters, renewable energy access capacity, reactive power compensation device parameters, operation mode and fault scenario data. The access node selection module is used to screen out the busbars in the target power grid that meet the short-circuit capacity weakness index, voltage weakness index, dynamic reactive power gap index, renewable energy access intensity index, and post-fault voltage recovery index as initial candidate access nodes. It constructs an evaluation index system, performs a comprehensive score on each node, and selects the node with the highest comprehensive score as the target node for accessing the synchronous condenser. The evaluation index system includes the short-circuit capacity weakness index, voltage weakness index, dynamic reactive power gap index, renewable energy access ratio index, and post-fault voltage recovery index. The configuration module is used to determine the configuration capacity of the synchronous condenser, the reactive power reference value, the reactive power coordination strategy with the reactive power compensation device, and the primary equipment access scheme. The simulation verification and iterative correction module is used to sequentially perform steady-state power flow and short-circuit capacity, electromechanical transient and electromagnetic transient simulation verification. When the verification indicators do not meet the preset requirements, the module iteratively corrects the access location, configuration capacity, reactive power reference value, primary equipment access scheme and reactive power coordination strategy of the synchronous condenser in the configuration module, and re-verifies until all verification indicators meet the requirements.

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