A method, apparatus, equipment, medium, and product for supporting transient voltage control in power grids.

Abstract

This application discloses a method, device, equipment, medium, and product for power grid transient voltage support control, relating to the field of power systems. The method includes: in the reactive power control stage, introducing a quasi-steady-state model simulating a synchronous condenser in the module generating voltage amplitude in the static var compensator (SVC), simulating the voltage change at the virtual condenser terminal during transient processes, and determining an improvement strategy for the reactive power control stage; in the phase-locked loop (PLL) stage based on power balance, improving the droop control stage of the SVC based on the swing equation, simulating the electromagnetic torque of the virtual condenser, adjusting phase information, and determining an improvement strategy for the PLL stage; based on the improved strategies for the reactive power control stage and the PLL stage, determining a power grid transient voltage support control strategy based on the virtual condenser to control the grid voltage. This application can solve the overcurrent phenomenon during fault processes and reduce the overvoltage level at the grid connection point after a fault.

Description

Technical Field

[0001] This application relates to the field of power systems, and in particular to a method, apparatus, equipment, medium, and product for supporting transient voltage in power grids. Background Technology

[0002] Among the reactive power compensation equipment equipped in new energy power plants, synchronous condensers (SC) and static synchronous compensators (STATCOMs) are representative. SCs can autonomously respond to the reactive power demand of the system, providing short-term overload currents several times their rated value, and have strong transient voltage stability capabilities. However, due to their high losses (typically reaching 1%-2% of rated power), high cost, and large footprint, SCs have been gradually replaced by reactive power compensation devices such as STATCOMs with the development of power electronics technology. STATCOMs, composed of power electronic devices, offer advantages such as continuous regulation, wide operating range, small footprint, low construction cost, fast regulation, and low operation and maintenance costs. Furthermore, when providing reactive power support to the system, their losses are less than 1% of the rated power.

[0003] While STATCOMs possess the aforementioned advantages, some inherent characteristics limit their application in practical engineering scenarios. Significant issues include the low reliability of STATCOMs during transient processes due to the inherent characteristics of power electronic devices, and the heavy reliance of STATCOMs on phase-locked loop (PLL) phase information for grid compensation. To improve STATCOM performance, the current mainstream approach is to modify the STATCOM control strategy from a grid-following model to a grid-connecting model, referencing the control structure of a virtual synchronous generator (VSG), thus simulating synchronous condensers. While this theoretically achieves the simulation of synchronous condensers, it lacks characterization of the transient processes of synchronous condensers, still exhibiting issues such as phase-locking inaccuracies, delayed reactive power reversion, and inability to address overcurrent problems at the STATCOM grid connection point during faults and overvoltage problems at the grid connection point after faults. Summary of the Invention

[0004] The purpose of this application is to provide a method, device, equipment, medium and product for supporting control of transient voltage in power grids, so as to solve the overcurrent problem of the STATCOM grid connection point during the fault process and the overvoltage problem of the grid connection point after the fault.

[0005] To achieve the above objectives, this application provides the following solution:

[0006] In a first aspect, this application provides a method for supporting transient voltage control in a power grid, comprising:

[0007] In the reactive power control stage, a quasi-steady-state model simulating a synchronous condenser is introduced into the module that generates the voltage amplitude of the static var compensator. This model simulates the change in the voltage at the virtual synchronous condenser terminal during transient processes, thereby determining the improvement strategy for the reactive power control stage. The terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual synchronous condenser. The virtual synchronous condenser is a quasi-steady-state model.

[0008] In the phase-locked loop based on power balance, the droop control loop of the static var compensator is improved based on the swing equation, the electromagnetic torque of the virtual synchronous condenser is simulated, the phase information is adjusted, and the improvement strategy of the phase-locked loop is determined.

[0009] Based on the improved strategies for reactive power control and phase-locked loop, a grid transient voltage support control strategy based on a virtual synchronous condenser is determined to control the grid voltage.

[0010] Secondly, this application provides a power grid transient voltage support control device, comprising:

[0011] The reactive power control improvement module is used to introduce a quasi-steady-state model of a simulated synchronous condenser into the module that generates the voltage amplitude of the static var compensator in the reactive power control stage. This model simulates the change in the voltage at the virtual synchronous condenser terminal during transient processes and determines the improvement strategy for the reactive power control stage. The terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual synchronous condenser. The virtual synchronous condenser is a quasi-steady-state model.

[0012] The phase-locked loop improvement module based on power balance is used to improve the droop control loop of the static var compensator based on the swing equation in the phase-locked loop based on power balance, simulate the electromagnetic torque of the virtual synchronous condenser, adjust the phase information, and determine the phase-locked loop improvement strategy.

[0013] The grid voltage control module is used to determine a grid transient voltage support control strategy based on a virtual synchronous condenser, according to the improved strategies of the reactive power control link and the improved strategies of the phase-locked loop, so as to control the grid voltage.

[0014] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the power grid transient voltage support control method described in any one of the above.

[0015] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the power grid transient voltage support control method described in any one of the above descriptions.

[0016] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the power grid transient voltage support control method described above.

[0017] According to the specific embodiments provided in this application, the following technical effects are disclosed:

[0018] This application improves the existing grid-type STATCOM structure by introducing a quasi-steady-state model capable of characterizing the transient characteristics of synchronous motors into the STATCOM: Introducing a quasi-steady-state model into the voltage amplitude generation module can simulate the voltage changes at the synchronous condenser terminals during transient processes, reducing the intensity of voltage changes and thus making the transient reactive power output of the STATCOM smoother, resolving overcurrent phenomena during faults; Adding a stage for simulating the electromagnetic torque of the synchronous condenser to the phase-locked loop based on power balance improves transient phase-locking accuracy, reduces system reactive power redundancy caused by decreased phase-locking accuracy during transient processes, and thus mitigates the overvoltage level at the grid connection point after a fault. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a power grid transient voltage support control method provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of a STATCOM module for generating voltage amplitude after introducing a quasi-steady-state model, provided in an embodiment of this application.

[0022] Figure 3 This is a schematic diagram of a power-balance-based phase-locked strategy provided in an embodiment of this application;

[0023] Figure 4 This is a schematic diagram of a power grid transient voltage support control strategy based on a virtual synchronous condenser provided in an embodiment of this application;

[0024] Figure 5 This is a physical topology diagram of a virtual camera provided in an embodiment of this application. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0026] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] This application provides a method for controlling transient voltage in a power grid. This method is executed by a computer device, specifically a terminal or server, or both. In this application embodiment, for example... Figure 1 As shown, the method includes the following steps.

[0028] S1: In the reactive power control stage, in the module that generates the voltage amplitude of the static var compensator, a quasi-steady-state model of a simulated synchronous condenser is introduced to simulate the change of the virtual synchronous condenser terminal voltage during the transient process and determine the improvement strategy of the reactive power control stage; the terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual synchronous condenser; the virtual synchronous condenser is a quasi-steady-state model.

[0029] S2: In the phase-locked loop based on power balance, the droop control loop of the static var compensator is improved based on the swing equation, the electromagnetic torque of the virtual synchronous condenser is simulated, the phase information is adjusted, and the improvement strategy of the phase-locked loop is determined.

[0030] S3: Based on the improved strategies for reactive power control and phase-locked loop, determine the grid transient voltage support control strategy based on virtual synchronous condenser to control the grid voltage.

[0031] In one exemplary embodiment, such as Figure 2 As shown, S1 can be replaced by the following steps.

[0032] S11: Connect the AC bus voltage V and reactive power Q at the grid connection point of the static var compensator to the AC voltage reference value V. ref and reactive power reference value Q ref The comparison is performed, and the result is then passed through a current circuit and compared with the virtual rotor electromotive force reference value E. ref By subtracting the values, we obtain the virtual rotor electromotive force E;

[0033] S12: Input the virtual rotor electromotive force E into the quasi-steady-state model to obtain the direct-axis voltage u of the virtual rotor. rd and quadrature axis voltage u rqand for the direct-axis voltage u rd and quadrature axis voltage u rq By finding the root of the sum of squares, the reference voltage amplitude E of the static var compensator can be obtained. s This means that the simulation of the synchronous condenser is realized in the reactive power circuit input stage of STATCOM, the reactive power compensation performance of STATCOM in transient processes is enhanced, and the improvement strategy of the reactive power control stage is determined.

[0034] In an exemplary embodiment, S1 can be replaced by the following steps.

[0035] use The change in the voltage at the virtual synchronous condenser terminal during the simulated transient process is used to determine the improvement strategy for the reactive power control loop; the meaning of each letter is shown in Table 1.

[0036] Table 1

[0037]

[0038]

[0039] Furthermore, the above formula can be used to simulate the rotor quadrature-axis voltage and direct-axis voltage of the synchronous condenser, i.e., u rd and u rq Both can be jointly controlled by virtual resistance, virtual reactance, and virtual rotor voltage reference value. When the STATCOM outputs v d and v q When changes occur, u rd and u rq Not only does it change with the state of the power grid, but it also responds to changes in the power grid state based on its own operating status, thus simulating the transient process of a synchronous condenser during a power grid fault. Since the voltage amplitude of a STATCOM has only one input value, it can simulate u... rd and u rq The operation of finding the root of the sum of squares is used as the voltage amplitude input for STATCOM.

[0040] In an exemplary embodiment, based on the above improvements, the drooping element of the STATCOM is further improved based on the swing equation to simulate the working characteristics of the camera condenser, such as... Figure 3 As shown, S2 can be replaced by the following steps.

[0041] S21: Calculate the virtual mechanical torque T by passing the active power exchange value P between the static var compensator and the power grid through a current circuit. m And based on the direct-axis current i d Voltage v d Cross-axis current i q and voltage vq Calculate the virtual electromagnetic torque T e And the reactive power output value Q of the static var compensator.

[0042] S22: The virtual mechanical torque T m and virtual electromagnetic torque T e The difference is used as the input of the droop control loop, and the difference is integrated and divided by the inertia coefficient J to obtain the angular velocity of the virtual rotor; the angular velocity of the virtual rotor is the output angular frequency ω of the static var compensator.

[0043] S23: Combine the output angular frequency ω with the angular velocity reference value ω ref The difference multiplied by the following vertical coefficient D p This feedback is sent to the droop control loop to update the output angular frequency ω.

[0044] S24: Determine the phase of the static var compensator based on the updated output angular frequency ω'.

[0045] S25: Determine whether the phase of the static var compensator is the same as the phase frequency of the power grid; if yes, complete the phase-locking process; if no, return to S22 until the phase of the static var compensator is the same as the phase frequency of the power grid.

[0046] In an exemplary embodiment, S2 can be replaced by the following steps.

[0047] use The electromagnetic torque of the virtual phase shifter is simulated, the phase information is adjusted, and the phase-locked loop improvement strategy is determined; the meaning of each letter is shown in Table 2.

[0048] Table 2

[0049]

[0050]

[0051] The phase-locked loop (PLL) primarily provides the STATCOM with frequency and phase information from the power grid. Based on power balance, the PLL adjusts its own phase information by detecting the active power exchange between the STATCOM and the grid: when the active power exchange is zero, it indicates that the STATCOM has completed phase locking with the grid; otherwise, it adjusts its own phase, absorbing / injecting active power until the STATCOM's phase and frequency are synchronized with the grid, thus completing the entire phase-locking process.

[0052] The new phase-locked loop (PLL) strategy aims to control the active power exchange between the STATCOM and the grid to zero. It replaces the traditional SRF-PLL, which uses a phase detector to directly obtain the grid phase by comparison, with a power balance-based PLL. By calculating the grid phase based on its own operating mode, the strategy can reduce the interference of transient AC components on the PLL during faults, improve the PLL accuracy during faults, and thus enhance the transient reactive power compensation capability of the STATCOM.

[0053] In one exemplary embodiment, such as Figure 4 As shown, S3 can be replaced by the following steps.

[0054] S31: Based on the phase θ of the static var compensator, perform dq decomposition on the grid connection point voltage to obtain the d-axis voltage u of the grid connection point. gd and q-axis voltage u gq And input it into the reactive power control loop.

[0055] S32: In the reactive power control stage, the d-axis voltage u of the grid connection point is... gd and q-axis voltage u gq The voltage amplitude is calculated to be E using a quasi-steady-state model. s The three-phase voltage.

[0056] S33: Perform dq decomposition on the three-phase voltage to obtain the direct-axis input voltage u of the current loop. sd and quadrature axis input voltage u sq And by decoupling through a current loop, the reference voltage v required for sinusoidal pulse width modulation is obtained. dref and v qref This allows the static var compensator to provide reactive power support according to the needs of the power grid.

[0057] Figure 4 The meanings of the letters involved are shown in Table 3.

[0058] Table 3

[0059] <![CDATA[V dc ]]> DC side voltage <![CDATA[V dcref ]]> DC side voltage reference value <![CDATA[i sd ]]> STATCOM output direct-axis current <![CDATA[i sq ]]> STATCOM output quadrature axis current L Grid connection point filter inductance value <![CDATA[v dref ]]> SPWM reference direct-axis voltage <![CDATA[v qref ]]> SPWM reference quadrature voltage <![CDATA[L rd ]]> Virtual rotor direct-axis inductance <![CDATA[L rq ]]> Virtual rotor quadrature axis inductance

[0060] Furthermore, Figure 2 The reactive power control stage is mainly responsible for generating the amplitude E of the reference voltage. s , Figure 3 The power phase-locked loop (PLL) is responsible for calculating the phase of the equipment itself. The reactive power control loop generates an amplitude of E. s The three-phase voltage is obtained, and the phase generated by the power balance phase-locked loop is decomposed into dq values ​​to generate the input voltage u of the inner current loop. sd u sq Then, by decoupling the current inner loop from the filter inductor, the reference input voltage of SPWM is generated, thereby achieving control of the converter.

[0061] Combination Figure 4 The specific analysis of this application is as follows:

[0062] Step 1: Measure the amplitude V of the STATCOM grid connection point voltage, reactive power Q, active power P, and direct-axis voltage v. d Current i d Cross-axis voltage v q Current i q .

[0063] Step 2: V, Q, v d and v q The reactive power control circuit is used to calculate the amplitude E of the three-phase voltage that should be output at this time. s ;P, v d v q Input power balance phase-locked loop, calculate virtual mechanical torque T m Virtual electromagnetic torque T e After undergoing a droop phase, the angular velocity ω and phase θ of the output STATCOM are used, and combined with the three-phase voltage generated by the reactive power control loop, a dq decomposition is performed to generate the input voltage u of the current loop in the dq coordinate system. sd u sq .

[0064] Step 3: Current loop to u sd and u sq And decouple it to generate the SPWM reference voltage v dref v qref This allows for the control of the converter.

[0065] Step 4: When the active power exchange between the STATCOM and the grid is 0, it indicates that phase locking is complete; when the voltage amplitude output by the STATCOM no longer changes, it indicates that the reactive power exchange meets the system requirements. If the active power exchange is not 0 or the voltage amplitude fluctuates, repeat steps 2 and 3 until the requirements are met.

[0066] The following is combined with Figure 4 and Figure 5 This paper explains the reactive power interaction between the virtual synchronous condenser and the power grid, and elaborates on the reactive power support process of the virtual synchronous condenser control strategy when the power grid fails.

[0067] like Figure 4 As shown, the DC-side capacitor is connected to the power grid through the converter and the grid-connected filter inductor. The virtual synchronous condenser controls the DC-axis voltage v of the converter according to the change in the grid connection point voltage. d The magnitude of the voltage is used to control the active power exchange between the STATCOM and the grid, and to control the quadrature-axis voltage V. q The size of the reactive power exchange between the system and the power grid is controlled by the size of the reactive power exchange.

[0068] When a power grid fault occurs, the exchange of active power between the capacitor and the grid causes a change in the DC-side voltage. Figure 4 Virtual mechanical torque T of medium power drooping element m and virtual electromagnetic torque T e The changes will occur synchronously, adjusting the angular velocity ω and phase θ of the virtual rotor.

[0069] The phase difference between the virtual synchronous condenser and the power grid changes from 0 in steady state: if the virtual synchronous condenser absorbs active power and injects reactive power from the power grid, it means that its phase is ahead of the power grid phase. The virtual synchronous condenser supports the power grid voltage by inputting reactive current into the power grid. Conversely, if the virtual synchronous condenser injects active power into the power grid and absorbs reactive power, it means that its phase is behind the power grid phase. The virtual synchronous condenser absorbs excess reactive current in the power grid, thereby absorbing reactive power, reducing the overvoltage level, and achieving overvoltage mitigation after a fault.

[0070] After obtaining the phase information θ, the grid connection point voltage is decomposed into dq values ​​based on θ to obtain the d-axis voltage u of the grid connection point. gd and q-axis voltage u gq And input the reactive power control loop. Based on the obtained u gd and u \gq The reactive power control loop is calculated by the quasi-steady-state model and outputs an amplitude of E. s The three-phase voltages a, b, and c are then decomposed using dq decomposition to obtain the direct-axis input voltage u of the current loop. sd and quadrature axis input voltage u sq Finally, decoupling is performed using a current loop to obtain the reference voltage v required for SPWM. dref and v qref This enables STATCOM to provide reactive power support according to the needs of the power grid.

[0071] During a fault, the quasi-steady-state model can incorporate damping in the reactive current reference value calculation to prevent sudden changes in the reactive current reference value, thereby mitigating the overcurrent level of the converter during the fault duration. Similarly, during the fault recovery phase, the rate of change of the reactive current reference value can be slowed down, ensuring that the equipment supports the grid with a larger reactive current level, thus reducing the overvoltage level during the fault recovery process when the reactive power generation / absorption is constant.

[0072] In addition, the virtual phase-locked loop adopts a power-balanced phase-locking strategy in the phase-locking stage. Compared with the traditional phase-locked loop (SRF-PLL), the power-balanced phase-locking strategy can reduce the impact of transient AC components on the accuracy of transient phase-locking. On the other hand, the operation logic is simple and the speed of transient phase-locking is improved.

[0073] Based on the same inventive concept, this application also provides a power grid transient voltage support control device for implementing the aforementioned power grid transient voltage support control method. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the power grid transient voltage support control device provided below can be found in the limitations of the power grid transient voltage support control method described above, and will not be repeated here.

[0074] In one exemplary embodiment, a power grid transient voltage support control device is provided, comprising:

[0075] The reactive power control improvement module is used to introduce a quasi-steady-state model of a simulated synchronous condenser into the module that generates the voltage amplitude of the static var compensator in the reactive power control stage. This model simulates the change in the voltage at the virtual synchronous condenser terminals during transient processes and determines the improvement strategy for the reactive power control stage. The terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual synchronous condenser. The virtual synchronous condenser is a quasi-steady-state model.

[0076] The phase-locked loop improvement module based on power balance is used to improve the droop control loop of the static var compensator based on the swing equation in the phase-locked loop based on power balance, simulate the electromagnetic torque of the virtual synchronous condenser, adjust the phase information, and determine the phase-locked loop improvement strategy.

[0077] The grid voltage control module is used to determine a grid transient voltage support control strategy based on a virtual synchronous condenser, according to the improved strategies of the reactive power control link and the improved strategies of the phase-locked loop, so as to control the grid voltage.

[0078] In an exemplary embodiment, a computer device is provided, which may be a server or a terminal. The computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is connected to the system bus via the I / O interfaces. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the computer device stores power grid transient voltage support control data. The I / O interfaces of the computer device are used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it implements a power grid transient voltage support control method.

[0079] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described above.

[0080] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the methods described above.

[0081] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the methods described above.

[0082] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0083] In this application, all actions to acquire signals, information, or data are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with the authorization granted by the owner of the relevant device.

[0084] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0085] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0086] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for supporting control of transient voltage in a power grid, characterized in that, The power grid transient voltage support control method includes: In the reactive power control stage, a quasi-steady-state model simulating a synchronous condenser is introduced into the module that generates the voltage amplitude of the static var compensator. This model simulates the change in the voltage at the virtual synchronous condenser terminal during transient processes, thereby determining the improvement strategy for the reactive power control stage. The terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual synchronous condenser. The virtual synchronous condenser is a quasi-steady-state model. In the phase-locked loop based on power balance, the droop control loop of the static var compensator is improved based on the swing equation, the electromagnetic torque of the virtual synchronous condenser is simulated, the phase information is adjusted, and the improvement strategy of the phase-locked loop is determined. Based on the improved strategies for reactive power control and phase-locked loop, a grid transient voltage support control strategy based on a virtual synchronous condenser is determined to control the grid voltage.

2. The power grid transient voltage support control method according to claim 1, characterized in that, In the reactive power control stage, a quasi-steady-state model simulating a synchronous condenser is introduced into the module that generates the voltage amplitude of the static var compensator. This model simulates the change in the voltage at the virtual synchronous condenser terminal during transient processes, and determines the improvement strategy for the reactive power control stage, specifically including: The AC bus voltage V and reactive power Q at the grid connection point of the static var compensator are compared with the AC voltage reference value V. ref and reactive power reference value Q ref The comparison is performed, and the result is then passed through a current circuit and compared with the virtual rotor electromotive force reference value E. ref By subtracting the values, we obtain the virtual rotor electromotive force E; The virtual rotor electromotive force E is input into the quasi-steady-state model to obtain the direct-axis voltage u of the virtual rotor. rd and quadrature axis voltage u rq and for the direct-axis voltage u rd and quadrature axis voltage u rq By finding the root of the sum of squares, the reference voltage amplitude E of the static var compensator can be obtained. s The improvement strategy for the reactive power control loop is determined.

3. The power grid transient voltage support control method according to claim 2, characterized in that, In the reactive power control stage, a quasi-steady-state model simulating a synchronous condenser is introduced into the module that generates the voltage amplitude of the static var compensator. This model simulates the change in the voltage at the virtual synchronous condenser terminal during transient processes, and determines the improvement strategy for the reactive power control stage, specifically including: use Simulate the change in voltage at the virtual synchronous condenser terminal during a transient process to determine improvement strategies for the reactive power control loop; where R v For virtual rotor resistance; v d This is the direct-axis voltage at the grid connection point; v q X is the quadrature-axis voltage at the grid connection point; v For virtual rotor reactance; m q k is the rotor electromotive force droop coefficient. pr k is the proportional coefficient of the virtual rotor electromotive force element. ir The integral coefficient of the virtual rotor electromotive force element.

4. The power grid transient voltage support control method according to claim 3, characterized in that, In the phase-locked loop (PLL) based on power balance, the droop control loop of the static var compensator (SVC) is improved based on the swing equation. This involves simulating the electromagnetic torque of the virtual synchronous condenser, adjusting the phase information, and determining the improved PLL strategy, specifically including: The active power exchange value P between the static var compensator and the power grid is passed through a current circuit to calculate the virtual mechanical torque T. m And based on the direct-axis current i d Voltage v d Cross-axis current i q and voltage v q Calculate the virtual electromagnetic torque T e And the reactive power output value Q of the static var compensator; virtual mechanical torque T m and virtual electromagnetic torque T e The difference is used as the input of the droop control loop, and the difference is integrated and divided by the inertia coefficient J to obtain the angular velocity of the virtual rotor; the angular velocity of the virtual rotor is the output angular frequency ω of the static var compensator. The output angular frequency ω is compared with the angular velocity reference value ω. ref The difference multiplied by the following vertical coefficient D p The feedback is sent to the droop control loop to update the output angular frequency ω; The phase of the static var compensator is determined based on the updated output angular frequency ω'. Determine whether the phase frequency of the static var compensator is the same as that of the power grid; if yes, complete the phase-locking process; if no, return to "set virtual mechanical torque T". m and virtual electromagnetic torque T e The difference is used as the input of the droop control loop, and the difference is integrated and divided by the inertia coefficient J to obtain the angular velocity of the virtual rotor until the phase of the static var compensator is the same as the phase frequency of the power grid.

5. The power grid transient voltage support control method according to claim 4, characterized in that, In the phase-locked loop (PLL) based on power balance, the droop control loop of the static var compensator (SVC) is improved based on the swing equation. This involves simulating the electromagnetic torque of the virtual synchronous condenser, adjusting the phase information, and determining the improved PLL strategy, specifically including: use Simulate the electromagnetic torque of the virtual phase shifter, adjust the phase information, and determine the improvement strategy for the phase-locked loop; wherein, ψ f For virtual flux linkage; e is the terminal voltage of the static var compensator; θ is the phase of the static var compensator; p n This represents the number of pole pairs in the synchronous machine.

6. The power grid transient voltage support control method according to claim 5, characterized in that, Based on the improved strategies for reactive power control and phase-locked loop, a grid transient voltage support control strategy based on a virtual synchronous condenser is determined to control the grid voltage, specifically including: Based on the phase θ of the static var compensator, the grid connection point voltage is decomposed into dq values ​​to obtain the d-axis voltage u at the grid connection point. gd and q-axis voltage u gq And input it into the reactive power control loop; In the reactive power control stage, the d-axis voltage u at the grid connection point is... gd and q-axis voltage u gq The voltage amplitude is calculated to be E using a quasi-steady-state model. s The three-phase voltage; The three-phase voltage is decomposed using dq decomposition to obtain the direct-axis input voltage u of the current loop. sd and quadrature axis input voltage u sq And by decoupling through a current loop, the reference voltage v required for sinusoidal pulse width modulation is obtained. dref and v qref This allows the static var compensator to provide reactive power support according to the needs of the power grid.

7. A power grid transient voltage support control device, characterized in that, The power grid transient voltage support control device includes: The reactive power control improvement module is used to introduce a quasi-steady-state model of a simulated synchronous condenser into the module that generates the voltage amplitude of the static var compensator in the reactive power control stage. This model simulates the change in the voltage at the virtual synchronous condenser terminal during transient processes and determines the improvement strategy for the reactive power control stage. The terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual synchronous condenser. The virtual synchronous condenser is a quasi-steady-state model. The phase-locked loop improvement module based on power balance is used to improve the droop control loop of the static var compensator based on the swing equation in the phase-locked loop based on power balance, simulate the electromagnetic torque of the virtual synchronous condenser, adjust the phase information, and determine the phase-locked loop improvement strategy. The grid voltage control module is used to determine a grid transient voltage support control strategy based on a virtual synchronous condenser, according to the improved strategies of the reactive power control link and the improved strategies of the phase-locked loop, so as to control the grid voltage.

8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the power grid transient voltage support control method according to any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the power grid transient voltage support control method according to any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the power grid transient voltage support control method according to any one of claims 1-6.

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