Power grid transient voltage support control method, device, equipment, medium and product

Abstract

The invention discloses a power grid transient voltage support control method, device, equipment, medium and product, and relates to the field of electric power systems.The method comprises the steps that in the reactive power control link, a quasi-steady-state model for simulating a synchronous phase modifier is introduced into a voltage amplitude generation module of a static var compensator, the change of the terminal voltage of the virtual phase modifier in the transient process is simulated, and a reactive power control link improvement strategy is determined; in a phase locking link based on power balance, a droop control link of the static var compensator is improved based on a wobble equation, the electromagnetic torque of the virtual phase modifier is simulated, phase information is adjusted, and a phase locking link improvement strategy is determined; and according to the reactive power control link improvement strategy and the phase-locked link improvement strategy, determining a power grid transient voltage support control strategy based on the virtual phase modifier so as to control the power grid voltage, thereby solving the overcurrent phenomenon in the fault process, and reducing the overvoltage level of the grid-connected point after the fault.

Description

Technical Field

[0001] The present application relates to the field of power systems, and in particular to a method, device, equipment, medium and product for controlling transient voltage support of a power grid. Background Art

[0002] Among the reactive power compensation equipment equipped in new energy stations, synchronous condenser (SC) and static synchronous compensator (STATCOM) are representative. Synchronous condenser can respond to the reactive power demand of the system autonomously, provide short-term overload current several times the rated value, and have strong transient voltage stability operation capability. However, due to the high loss of synchronous condenser, which can usually reach 1%-2% of the rated power, the high cost and large floor space, with the development of power electronics technology, it has been gradually replaced by reactive power compensation devices such as STATCOM. STATCOM composed of power electronic devices has the advantages of continuous regulation, wide operating range, small floor space, low construction cost, fast regulation, low operation and maintenance cost, and when providing reactive power support to the system, the loss is less than 1% of the rated power.

[0003] Although STATCOM has the above advantages, some of its own characteristics also limit its application in actual engineering scenarios. Among them, the more significant problems include the low reliability of STATCOM in transient processes due to the characteristics of power electronic devices themselves, and the fact that the compensation effect of STATCOM on the power grid is heavily dependent on the phase information obtained by the phase-locked loop. In order to improve the performance of STATCOM, the current mainstream approach is to refer to the control structure of the virtual synchronous generator (VSG), transform the control strategy of STATCOM from a grid-following type to a grid-building type, and realize the simulation of synchronous condensers. Although this method realizes the simulation of synchronous condensers in principle, it lacks the characterization of the transient process of synchronous condensers, and there are still situations of phase misalignment and untimely reactive power withdrawal, which cannot solve the overcurrent problem of the STATCOM grid-connected point during the fault process and the overvoltage problem of the grid-connected point after the fault. Summary of the invention

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

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

[0006] In a first aspect, the present application provides a method for controlling transient voltage support of a power grid, comprising:

[0007] In the reactive power control link, in the module of generating voltage amplitude of static VAR compensator, a quasi-steady-state model simulating synchronous condenser is introduced to simulate the change of terminal voltage of virtual condenser in transient process, and the improvement strategy of reactive power control link is determined; the terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of virtual condenser; the virtual condenser is a quasi-steady-state model;

[0008] In the phase-locked link based on power balance, the droop control link of the static VAR compensator is improved based on the swing equation, the electromagnetic torque of the virtual phase regulator is simulated, the phase information is adjusted, and the phase-locked link improvement strategy is determined;

[0009] According to the reactive power control link improvement strategy and the phase-locked link improvement strategy, a grid transient voltage support control strategy based on a virtual phase regulator is determined to control the grid voltage.

[0010] In a second aspect, the present application provides a power grid transient voltage support control device, comprising:

[0011] The reactive power control link improvement module is used to introduce a quasi-steady-state model simulating a synchronous phase condenser in a module generating a voltage amplitude in a static VAR compensator in a reactive power control link, simulate the change of the terminal voltage of the virtual phase condenser in a transient process, and determine the improvement strategy of the reactive power control link; the terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual phase condenser; the virtual phase condenser is a quasi-steady-state model;

[0012] A power balance-based phase-locked link improvement module is used to improve the droop control link of the static VAR compensator based on the swing equation in the power balance-based phase-locked link, simulate the electromagnetic torque of the virtual phase regulator, adjust the phase information, and determine the phase-locked link improvement strategy;

[0013] The grid voltage control module is used to determine the grid transient voltage support control strategy based on the virtual phase regulator according to the reactive power control link improvement strategy and the phase-locked link improvement strategy to control the grid voltage.

[0014] In a third aspect, the present application provides a computer device comprising: 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 any of the above-described methods for transient voltage support control of a power grid.

[0015] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for controlling transient voltage support of a power grid.

[0016] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any of the above-mentioned methods for transient voltage support control of a power grid.

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

[0018] The present application improves the original grid-type STATCOM structure by introducing a quasi-steady-state model that can characterize the transient characteristics of the synchronous motor on the STATCOM: the introduction of the quasi-steady-state model in the module for generating voltage amplitude can simulate the change of the terminal voltage of the synchronous phase-converter during the transient process, reduce the intensity of the voltage change during the transient process, and thus make the transient reactive power output of the STATCOM smoother and solve the overcurrent phenomenon during the fault process; a link for simulating the electromagnetic torque of the synchronous phase-converter is added to the phase-locking link based on power balance to improve the transient phase-locking accuracy, reduce the system reactive redundancy caused by the decrease in phase-locking accuracy during the transient process, and thus reduce the overvoltage level of the grid connection point after the fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A flow chart of a method for controlling transient voltage support in a power grid provided in an embodiment of the present application;

[0021] Figure 2 A schematic diagram of a module for generating voltage amplitude of a STATCOM after introducing a quasi-steady-state model provided in an embodiment of the present application;

[0022] Figure 3 A schematic diagram of a phase-locking strategy based on power balance provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of a transient voltage support control strategy for a power grid based on a virtual phase regulator provided in an embodiment of the present application;

[0024] Figure 5 This is a physical topology diagram of a virtual phase regulator provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0027] The present application embodiment provides a method for controlling transient voltage support of a power grid, which is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or can be executed by a terminal and a server together. In the present application embodiment, Figure 1 As shown, the method includes the following steps.

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

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

[0030] S3: According to the reactive power control link improvement strategy and the phase-locked link improvement strategy, a grid transient voltage support control strategy based on a virtual phase regulator is determined to control the grid voltage.

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

[0032] S11: Compare the AC bus voltage V and reactive power Q of the static VAR compensator grid connection point with the AC voltage reference value V ref and reactive power reference value Q ref The comparison is then made and the comparison result is compared with the virtual rotor electromotive force reference value E after passing through the current link. ref Make a difference and get the virtual rotor electromotive force E;

[0033] S12: Input the virtual rotor electromotive force E into the quasi-steady-state model to obtain the virtual rotor direct-axis voltage u rd and the quadrature axis voltage u rq, and the direct axis voltage u rd and the quadrature axis voltage u rq The square root of the sum of the squares is obtained to obtain the reference voltage amplitude E of the static VAR compensator. s That is, the simulation of the synchronous phase regulator in the reactive circuit input link of STATCOM is realized, the reactive compensation performance of STATCOM in the transient process is enhanced, and the determination of the improvement strategy of the reactive control link is completed.

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

[0035] use The change of the terminal voltage of the virtual phase-converter in the transient process is simulated to determine the improvement strategy of the reactive power control link; 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, that is, u rd and u rq , both of which can be controlled by virtual resistance, virtual reactance and virtual rotor voltage reference. d and v q When changes occur, u rd and u rq It not only changes with the state of the power grid, but also responds to the change of the power grid state according to its own operating state, so as to simulate the transient process of the synchronous condenser at the moment of power grid failure. rd and u rq The root of the square sum is taken as the voltage amplitude input of STATCOM.

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

[0041] S21: Calculate the virtual mechanical torque T by using the active power exchange value P between the static VAR compensator and the power grid through the current link m , and according to the direct axis current i d 、Voltage d , quadrature axis current i q And the voltage vq , calculate the virtual electromagnetic torque T e And the reactive 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 link, 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: Compare the output angular frequency ω with the angular velocity reference value ω ref The difference is multiplied by the droop coefficient D p , fed back to the droop control link to update the output angular frequency ω.

[0044] S24: Determine the phase of the static VAR compensator according to 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 so, complete the phase locking process; if not, 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 may be replaced by the following steps.

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

[0048] Table 2

[0049]

[0050]

[0051] The phase-locked link mainly provides STATCOM with the frequency and phase information of the power grid. The phase-locked link based on power balance adjusts its own phase information by detecting the active power exchange between STATCOM and the power grid: when the active power exchange is 0, it means that STATCOM has completed the phase lock with the power grid; otherwise, it adjusts its own phase and absorbs / injects active power until the phase and frequency of STATCOM are synchronized with the power grid, completing the entire phase locking process.

[0052] The new phase-locked strategy aims to control the active power exchange between STATCOM and the power grid to 0. The traditional SRF-PLL phase-locked link that uses a phase detector to directly obtain the grid phase through comparison is replaced by a phase-locked link based on power balance. The grid phase is obtained by calculating its own operating mode. This can reduce the interference of transient AC components on the phase-locked link during faults, improve the phase-locked accuracy during faults, and thus enhance the transient reactive power compensation capability of STATCOM.

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

[0054] S31: Perform dq decomposition on the grid connection point voltage based on the phase θ of the static VAR compensator to obtain the d-axis voltage u of the grid connection point gd and q-axis voltage u gq , and input into the reactive power control link.

[0055] S32: In the reactive power control link, the d-axis voltage u gd and q-axis voltage u gq The voltage amplitude calculated by the quasi-steady-state model is E 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 decoupled through the current loop to obtain the reference voltage v required for sinusoidal pulse width modulation dref and v qref , so that the static VAR compensator can perform reactive 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 link in the circuit is mainly responsible for generating the reference voltage amplitude E s , Figure 3 The power phase-locked link in the PWM is responsible for calculating the phase of the device itself. The reactive power control link generates an amplitude of E s The three-phase voltage is combined with the phase generated by the power balance phase-locked link to perform dq decomposition to generate the input voltage u of the inner current loop sd 、u sq , and then decoupled from the filter inductor through the current inner loop to generate the reference input voltage of SPWM, thereby achieving control of the converter.

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

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

[0063] Step 2: V, Q, v d and v q Enter the reactive power control link and 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 link to calculate virtual mechanical torque T m , virtual electromagnetic torque T e , after the droop link, the angular velocity ω and phase θ of the STATCOM are output, and the three-phase voltage generated by the reactive power control link is combined for dq decomposition 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 to generate the SPWM reference voltage v dref 、v qref Then control the inverter.

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

[0066] Combine the following Figure 4 and Figure 5 The reactive interaction relationship between the virtual phase regulator and the power grid is explained, and the reactive support process of the virtual phase regulator control strategy when a power grid failure occurs is elaborated in detail.

[0067] like Figure 4 As shown, the DC side capacitor is connected to the grid through the converter and the grid-connected filter inductor. The virtual phase regulator controls the direct axis voltage v of the converter according to the change of the grid-connected point voltage. d The size of the active power exchange between STATCOM and the power grid is controlled to control the quadrature axis voltage v q The size of the reactive power exchange between it and the grid is controlled.

[0068] When a fault occurs in the power grid, the active power exchange between the capacitor and the power grid will cause the DC side voltage to change. Figure 4 Virtual mechanical torque T of medium power droop link m and virtual electromagnetic torque T e will change synchronously, adjusting the angular velocity ω and phase θ of the virtual rotor.

[0069] The phase difference between the virtual phase regulator and the power grid will change from 0 in the steady state: if the virtual phase regulator absorbs active power from the power grid and injects reactive power, it means that its phase is ahead of the power grid phase at this time, and the virtual phase regulator supports the power grid voltage by inputting reactive current into the power grid; conversely, if the virtual phase regulator injects active power into the power grid and absorbs reactive power, it means that its phase lags behind the power grid phase at this time, and the virtual phase regulator absorbs excess reactive current in the power grid, thereby absorbing reactive power, reducing the level of overvoltage and achieving overvoltage smoothing after a fault.

[0070] After obtaining the phase information θ, the grid-connected point voltage is decomposed into dq based on θ to obtain the d-axis voltage u of the grid-connected point. gd and q-axis voltage u gq , and input the reactive power control link. According to the obtained u gd and u \gq The reactive power control link is calculated by the quasi-steady-state model and the output amplitude is E s The abc three-phase voltage is then decomposed into dq to obtain the direct axis input voltage u of the current loop. sd and quadrature axis input voltage u sq Finally, the current loop is decoupled to obtain the reference voltage v required by SPWM. dref and v qref , so that STATCOM can provide reactive power support according to the needs of the power grid.

[0071] During the fault process, the quasi-steady-state model can add a certain amount of damping to the reactive current reference value calculation link to prevent the reactive current reference value from changing suddenly, thereby reducing the overcurrent level of the converter during the fault period. Similarly, during the fault recovery phase, the change rate of the reactive current reference value can be slowed down to ensure that the equipment supports the grid with a larger reactive current level, and reduce the overvoltage level during the fault recovery process when the reactive power emitted / absorbed is constant.

[0072] In addition, the virtual phase regulator adopts a phase-locking strategy based on power balance in the phase-locking link. Compared with the traditional phase-locked loop (SRF-PLL), the phase-locking strategy based on power balance can reduce the impact of transient AC components on transient phase-locking accuracy on the one hand; on the other hand, the operation logic is simple, which improves the speed of transient phase locking.

[0073] Based on the same inventive concept, the embodiment of the present application also provides a power grid transient voltage support control device for implementing the power grid transient voltage support control method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more power grid transient voltage support control device embodiments provided below can refer to the limitations of the power grid transient voltage support control method above, and will not be repeated here.

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

[0075] The reactive power control link improvement module is used to introduce a quasi-steady-state model of a simulated synchronous phase regulator into a module that generates voltage amplitude in a static VAR compensator in the reactive power control link, simulate the change of the terminal voltage of the virtual phase regulator during the transient process, and determine the improvement strategy of the reactive power control link; the terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual phase regulator; the virtual phase regulator is a quasi-steady-state model.

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

[0077] The grid voltage control module is used to determine the grid transient voltage support control strategy based on the virtual phase regulator according to the reactive power control link improvement strategy and the phase-locked link improvement strategy 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, a memory, an input / output interface (I / O for short) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store power grid transient voltage support control data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a power grid transient voltage support control method is implemented.

[0079] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the above method is implemented when the processor executes the computer program.

[0080] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, which implements the above method when executed by a processor.

[0081] In an exemplary embodiment, a computer program product is provided, including a computer program, which implements the above method when executed by a processor.

[0082] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (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 (Magnetoresistive Random Access Memory, MRAM), ferroelectric random access memory (Ferroelectric Random Access Memory, FRAM), phase change memory (Phase Change Memory, PCM), graphene memory, etc. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0083] In this application, all actions to obtain signals, information or data are carried out in compliance with the relevant data protection laws and policies of the country where they are located and with the authorization given by the owner of the corresponding device.

[0084] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0085] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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 article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application; at the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for controlling transient voltage support of a power grid, characterized in that: The grid transient voltage support control method comprises: In the reactive power control link, in the module of generating voltage amplitude of static VAR compensator, a quasi-steady-state model simulating synchronous condenser is introduced to simulate the change of terminal voltage of virtual condenser in transient process, and the improvement strategy of reactive power control link is determined; the terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of virtual condenser; the virtual condenser is a quasi-steady-state model; In the phase-locked link based on power balance, the droop control link of the static VAR compensator is improved based on the swing equation, the electromagnetic torque of the virtual phase regulator is simulated, the phase information is adjusted, and the phase-locked link improvement strategy is determined; According to the reactive power control link improvement strategy and the phase-locked link improvement strategy, a grid transient voltage support control strategy based on a virtual phase regulator is determined to control the grid voltage.

2. The grid transient voltage support control method according to claim 1, characterized in that: In the reactive power control link, in the module of generating voltage amplitude of static VAR compensator, a quasi-steady-state model simulating synchronous condenser is introduced to simulate the change of terminal voltage of virtual condenser in transient process, and the improvement strategy of reactive power control link is determined, including: The AC bus voltage V and reactive power Q of the static VAR compensator grid connection point are compared with the AC voltage reference value V ref and reactive power reference value Q ref The comparison is then made and the comparison result is compared with the virtual rotor electromotive force reference value E after passing through the current link. ref Make a difference and get the virtual rotor electromotive force E; The virtual rotor electromotive force E is input into the quasi-steady-state model to obtain the virtual rotor direct axis voltage u rd and the quadrature axis voltage u rq , and the direct axis voltage u rd and the quadrature axis voltage u rq The square root of the sum of the squares is obtained to obtain the reference voltage amplitude E of the static VAR compensator. s , complete the determination of the improvement strategy for the reactive power control link.

3. The method for controlling transient voltage support of a power grid according to claim 2, characterized in that: In the reactive power control link, in the module of generating voltage amplitude of static VAR compensator, a quasi-steady-state model simulating synchronous condenser is introduced to simulate the change of terminal voltage of virtual condenser in transient process, and the improvement strategy of reactive power control link is determined, including: use Simulate the change of the terminal voltage of the virtual phase regulator in the transient process and determine the improvement strategy of the reactive power control link; v is the virtual rotor resistance; v d is the direct-axis voltage at the grid connection point; v q is the quadrature axis voltage at the grid connection point; X v is the virtual rotor reactance; m q is the rotor electromotive force droop coefficient; k pr k is the proportional coefficient of the virtual rotor electromotive force link; ir is the integral coefficient of the virtual rotor electromotive force link.

4. The method for controlling transient voltage support of a power grid according to claim 3, characterized in that: In the phase-locked link based on power balance, the droop control link of the static VAR compensator is improved based on the swing equation, the electromagnetic torque of the virtual phase regulator is simulated, the phase information is adjusted, and the phase-locked link improvement strategy is determined, which specifically includes: The active exchange value P between the static VAR compensator and the power grid is calculated through the current link to obtain the virtual mechanical torque T m , and according to the direct axis current i d 、Voltage d , quadrature axis current i q And the voltage v q , calculate the virtual electromagnetic torque T e And the reactive output value Q of the static VAR compensator; The virtual mechanical torque T m and virtual electromagnetic torque T e The difference is used as the input of the droop control link, 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 and the angular velocity reference value ω ref The difference is multiplied by the droop coefficient D p , fed back to the droop control link to update the output angular frequency ω; Determining the phase of the static VAR compensator according to the updated output angular frequency ω'; Determine whether the phase frequency of the static VAR compensator is the same as the phase frequency of the power grid; if so, complete the phase locking process; if not, return to "set the virtual mechanical torque T m and virtual electromagnetic torque T e The difference is used as the input of the droop control link, and the difference is integrated and divided by the inertia coefficient J to obtain the angular velocity of the virtual rotor ", until the phase frequency of the static VAR compensator is the same as the phase frequency of the power grid.

5. The method for controlling transient voltage support of a power grid according to claim 4, characterized in that: In the phase-locked link based on power balance, the droop control link of the static VAR compensator is improved based on the swing equation, the electromagnetic torque of the virtual phase regulator is simulated, the phase information is adjusted, and the phase-locked link improvement strategy is determined, which specifically includes: use Simulate the electromagnetic torque of the virtual phase regulator, adjust the phase information, and determine the phase-locked link improvement strategy; wherein, ψ f is the virtual flux; e is the terminal voltage of the static VAR compensator; θ is the phase of the static VAR compensator; p n is the number of synchronous machine pole pairs.

6. The method for controlling transient voltage support of a power grid according to claim 5, characterized in that: According to the reactive power control link improvement strategy and the phase-locked link improvement strategy, a grid transient voltage support control strategy based on a virtual phase regulator 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 to obtain the d-axis voltage u of the grid connection point. gd and q-axis voltage u gq , and input into the reactive power control link; In the reactive power control link, the d-axis voltage u gd and q-axis voltage u gq The voltage amplitude calculated by the quasi-steady-state model is E s The three-phase voltage; 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 decoupled through the current loop to obtain the reference voltage v required for sinusoidal pulse width modulation dref and v qref , so that the static VAR compensator can perform reactive support according to the needs of the power grid.

7. A power grid transient voltage support control device, characterized in that: The grid transient voltage support control device comprises: The reactive power control link improvement module is used to introduce a quasi-steady-state model simulating a synchronous phase condenser in a module generating a voltage amplitude in a static VAR compensator in a reactive power control link, simulate the change of the terminal voltage of the virtual phase condenser in a transient process, and determine the improvement strategy of the reactive power control link; the terminal voltage includes the rotor quadrature-axis voltage and direct-axis voltage of the virtual phase condenser; the virtual phase condenser is a quasi-steady-state model; A power balance-based phase-locked link improvement module is used to improve the droop control link of the static VAR compensator based on the swing equation in the power balance-based phase-locked link, simulate the electromagnetic torque of the virtual phase regulator, adjust the phase information, and determine the phase-locked link improvement strategy; The grid voltage control module is used to determine the grid transient voltage support control strategy based on the virtual phase regulator according to the reactive power control link improvement strategy and the phase-locked link improvement strategy 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, wherein the processor executes the computer program to implement the grid transient voltage support control method described in any one of claims 1 to 6.

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

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

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