Method and device for controlling internal potential of grid-connected static var generator

Abstract

The application provides a network-constructed static var generator internal potential control method and device, the method comprises the following steps: obtaining impedance characteristic data and grid-connected point voltage amplitude of the network-constructed static var generator SVG, the impedance characteristic data comprises grid voltage amplitude, grid voltage phase, internal potential amplitude and internal potential phase in steady-state operation; if the grid-connected point voltage amplitude is less than a low penetration limit value, it is determined that a transient fault occurs; the current grid voltage amplitude is determined according to the grid voltage drop depth and the grid voltage amplitude; the internal potential adjustment value is determined according to the impedance characteristic data, the current output current and the current grid voltage amplitude of the network-constructed static var generator; the internal potential of the network-constructed static var generator is controlled to be adjusted to the internal potential adjustment value, and the output current meets the overcurrent capacity limit condition, so that the rapid adjustment of the internal potential of the network-constructed SVG under the transient fault can be realized, and the rapid and accurate support of the network-constructed SVG reactive current is ensured.

Description

Technical Field

[0001] This application relates to the field of static var generator control technology, and in particular to a method and device for controlling the internal potential of a grid-type static var generator. Background Technology

[0002] Grid-Forming Static Reactive Power Generator (GFM-SVG) typically employs a power synchronization strategy similar to that of a synchronous generator. It can achieve synchronization without the need for a phase-locked loop, which can improve the active voltage support and rapid suppression of transient voltage in power grids with a high proportion of renewable energy sources, thus helping to increase the proportion of renewable energy used in the power grid.

[0003] Grid-type SVG exhibits voltage source characteristics externally. Key parameters in its control system include internal potential amplitude and phase angle. Under the virtual synchronous generation strategy, the internal potential amplitude is generated by a first-order inertial element based on the deviation between the reactive power reference value and the actual value. During grid voltage disturbances, the internal potential amplitude remains constant under the control system, while the grid-side voltage may change abruptly due to a fault. This causes a deviation between the internal potential amplitude of the grid-type SVG and the grid-side voltage amplitude at t=0+, resulting in a large reactive current. If this current is not limited, it will trigger the hardware protection of the device, causing a fault trip.

[0004] Current current limiting methods typically employ inner-loop current limiting or introduce virtual impedance and virtual admittance to limit the output current. However, these methods introduce second-order delay, causing the grid-type SVG to lose its voltage source characteristics. Furthermore, due to the poor adaptability of current limiting parameters, virtual impedance, and virtual admittance parameters, excessively large or small parameters can easily lead to the grid-type SVG failing to provide sufficient transient reactive power support or causing the output reactive current to be too large, resulting in device overcurrent and tripping faults. This fails to reflect the active voltage support characteristics of the grid-type SVG. Summary of the Invention

[0005] To address at least one problem in the prior art, this application proposes a method and apparatus for controlling the internal potential of a grid-type static var generator (SVG), which enables rapid adjustment of the internal potential of the grid-type SVG under transient faults, thereby ensuring rapid and accurate support of the reactive current of the grid-type SVG.

[0006] To address the aforementioned technical problems, this application provides the following technical solution:

[0007] In a first aspect, this application provides an internal potential control method for a grid-type static var generator, comprising:

[0008] Obtain the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation.

[0009] If the voltage amplitude at the grid connection point is less than the preset low-voltage limit, it is determined that the target grid-type static var generator has experienced a transient fault. The grid voltage drop depth is monitored, and the current grid voltage amplitude is determined based on the grid voltage drop depth and the grid voltage amplitude.

[0010] Obtain the current output current of the target grid-type static var generator, and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude;

[0011] The internal potential of the target grid-type static var generator is adjusted to the internal potential adjustment value so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition.

[0012] In one embodiment, determining the current grid voltage amplitude based on the grid voltage sag depth and the grid voltage amplitude includes:

[0013] The current grid voltage amplitude U is determined using the following formula. g1 :

[0014] U g1 =(1-p)U g0

[0015] Where p represents the voltage sag depth of the power grid, U g0 This indicates the voltage amplitude of the power grid.

[0016] In one embodiment, determining the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current, and the current grid voltage amplitude includes:

[0017] Determine the grid voltage phasor based on the grid voltage amplitude and grid voltage phase;

[0018] The internal potential phasor of the target grid-type static var generator is determined based on the internal potential amplitude and internal potential phase.

[0019] Based on the grid voltage phasor, internal potential phasor, and current output current, determine the real-time grid impedance value of the target grid-type static var generator;

[0020] Based on the real-time value of the grid impedance, the current grid voltage amplitude, and the pre-acquired rated current, the internal potential adjustment value of the target grid-type static var generator is determined.

[0021] In one embodiment, the internal potential control method for the grid-type static var generator further includes:

[0022] If the voltage at the grid connection point recovers to outside the preset hysteresis range, the internal potential of the target grid-type static var generator is adjusted to the internal potential phasor.

[0023] Secondly, this application provides an internal potential control device for a grid-type static var generator, comprising:

[0024] The acquisition module is used to acquire the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation.

[0025] The monitoring module is used to determine that the target grid-type static var generator has experienced a transient fault if the voltage amplitude at the grid connection point is less than a preset low-voltage limit, monitor the grid voltage drop depth, and determine the current grid voltage amplitude based on the grid voltage drop depth and the grid voltage amplitude.

[0026] The first determining module is used to obtain the current output current of the target grid-type static var generator, and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude.

[0027] The control module is used to control the internal potential of the target grid-type static var generator to be adjusted to the internal potential adjustment value, so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition.

[0028] In one embodiment, the monitoring module includes:

[0029] The monitoring unit is used to determine the current grid voltage amplitude U according to the following formula. g1 :

[0030] U g1 =(1-p)U g0

[0031] Where p represents the voltage sag depth of the power grid, U g0 This indicates the voltage amplitude of the power grid.

[0032] In one embodiment, the first determining module includes:

[0033] A voltage phasor unit is defined to determine the grid voltage phasor based on the grid voltage amplitude and grid voltage phase.

[0034] The internal potential phasor unit is determined to determine the internal potential phasor of the target grid-type static var generator based on the internal potential amplitude and internal potential phase.

[0035] The real-time impedance value determination unit is used to determine the real-time value of the grid impedance of the target grid-type static var generator based on the grid voltage phasor, internal potential phasor and current output current.

[0036] The adjustment value determination unit is used to determine the internal potential adjustment value of the target grid-type static var generator based on the real-time value of the grid impedance, the current grid voltage amplitude, and the pre-acquired rated current.

[0037] In one embodiment, the internal potential control device for the grid-type static var generator further includes:

[0038] The second determining module is used to adjust the internal potential of the target grid-type static var generator to the internal potential phasor if the voltage at the grid connection point recovers to outside the preset hysteresis range.

[0039] Thirdly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the internal potential control method of the grid-type static var generator.

[0040] Fourthly, this application provides a computer-readable storage medium storing computer instructions thereon, which, when executed by a processor, implement the internal potential control method for the grid-type static var generator.

[0041] As can be seen from the above technical solution, this application provides a method and apparatus for controlling the internal potential of a grid-type static var generator (SVM). The method includes: acquiring impedance characteristic data and grid connection point voltage amplitude of a target grid-type SVM, wherein the impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation; if the grid connection point voltage amplitude is less than a preset low-throughput limit, then determining that the target grid-type SVM has experienced a transient fault; monitoring the grid voltage sag depth; and determining the current grid voltage amplitude based on the grid voltage sag depth and the grid voltage amplitude; acquiring the current output current of the target grid-type SVM; and determining the internal potential adjustment value of the target grid-type SVM based on the impedance characteristic data, the current output current, and the current grid voltage amplitude; and controlling the internal potential of the target grid-type SVM to be adjusted to the internal potential adjustment value, so that the output current of the target grid-type SVM meets a preset overcurrent capacity limit condition. It enables rapid adjustment of the internal potential of the grid-type SVG under transient faults, thereby ensuring rapid and accurate reactive current support of the grid-type SVG; it eliminates the need for introducing additional virtual impedance and virtual admittance, avoiding second-order delay and improving the response speed and accuracy of the grid-type SVG; it allows for rapid adaptive adjustment of the internal potential of the grid-type SVG, ensuring automatic tracking and adjustment of the internal potential and grid voltage, achieving rapid and accurate reactive power support under transient faults, and ensuring that the grid-type SVG always maintains the operating characteristics of a voltage source. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0043] Figure 1 This is a first flowchart illustrating the internal potential control method for a grid-type static var generator in this application embodiment;

[0044] Figure 2 This is a second flowchart illustrating the internal potential control method for a grid-type static var generator in this application embodiment;

[0045] Figure 3 This is the equivalent circuit diagram of the grid-connected SVG in the application example of this application;

[0046] Figure 4 yes Figure 3 The equivalent circuit diagram of any power unit module in the diagram;

[0047] Figure 5 This is a schematic diagram of the hysteresis interval strategy used in the application example of this application for smoothing the exit of transient support of mesh-type SVG;

[0048] Figure 6 This is a flowchart illustrating the internal potential control method for a grid-type static var generator in an application example of this application.

[0049] Figure 7 This is a schematic diagram of the internal potential control device of the grid-type static var generator in the embodiments of this application;

[0050] Figure 8 This is a schematic block diagram of the system configuration of an electronic device according to an embodiment of this application. Detailed Implementation

[0051] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in 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 in 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.

[0052] Existing network-type SVGs are limited by the overcurrent capability of power devices (typically three times the overcurrent), and generally use virtual impedance in the control loop to achieve current limiting under transient faults. This method introduces impedance into the control loop, weakening the voltage source characteristics of the network-type SVG, and the parameters of the virtual impedance are difficult to adjust accurately, which greatly increases the control difficulty of the network-type SVG.

[0053] Voltage source characteristics refer to a device's ability to provide a stable voltage. When current inner-loop limiting is used, or virtual impedance and virtual admittance are introduced to limit the output current of a grid-connected SVG, a second-order delay occurs, affecting the SVG's response speed and accuracy. This effect causes the SVG to fail to provide the required reactive power in a timely and accurate manner, thus partially losing its voltage source characteristics and impacting its ability to support the power grid.

[0054] To address at least one problem in the existing technology, this application provides a method and apparatus for controlling the internal potential of a grid-type static var generator (SVG). This eliminates the need for current inner-loop limiting, the introduction of additional virtual impedance, and virtual admittance, thereby avoiding second-order delay and improving the response speed and accuracy of the SVG. The method and apparatus for controlling the internal potential of the SVG in this application can simulate the rapid excitation mode of a distributed synchronous condenser, enabling rapid adaptive adjustment of the SVG's internal potential. This ensures automatic tracking and adjustment of the SVG's internal potential with the grid voltage, achieving rapid and accurate reactive power support under transient faults, while ensuring the SVG maintains its voltage source operating characteristics. This method provides guidance for the control design, adaptive parameter tuning, and planning design of SVG, and also provides accurate reference for grid operators and dispatching departments regarding the fault voltage support capability of SVG.

[0055] The internal potential control method and apparatus for grid-type static var generators (SVG) according to embodiments of this application can realize rapid adaptive control of the internal potential of the grid-type SVG and its control parameter tuning. It can be applied to grid-type SVGs without an inner loop (Virtual Synchronous Generator, VSG). First, it performs rapid system voltage detection to accurately obtain the real-time voltage of the power grid; second, it constructs a real-time power grid strength assessment model and proposes a method for tuning the support parameters of the grid-type SVG under adaptive power grid strength; finally, it establishes a reactive current output function model between the internal potential and the system voltage to achieve rapid adjustment of the internal potential under transient faults, ensuring rapid and accurate support of reactive current for the grid-type SVG.

[0056] The embodiments of this application provide an internal potential control method and device for a grid-type static var generator (SVG). This method can ensure rapid and accurate reactive power support for the grid-type SVG under any voltage drop in the power grid. The control structure is simple and does not require complex logic algorithms, scene switching strategies, etc., and can provide a solution for transient control of grid-type SVG.

[0057] The following examples illustrate this in detail.

[0058] To achieve rapid adjustment of the internal potential of a grid-type static var generator (SVG) under transient faults, thereby ensuring rapid and accurate reactive current support, this embodiment provides an internal potential control method for a grid-type SVG, where the execution subject is an internal potential control device of the grid-type SVG. This internal potential control device for the grid-type SVG includes, but is not limited to, a server, such as... Figure 1 As shown, this method specifically includes the following:

[0059] Step 100: Obtain the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation.

[0060] Specifically, the internal potential amplitude can represent the internal potential amplitude of the target grid-type static var generator, and the internal potential phase can represent the internal potential phase of the target grid-type static var generator.

[0061] Step 200: If the voltage amplitude at the grid connection point is less than the preset low-voltage limit, it is determined that the target grid-type static var generator has experienced a transient fault. The grid voltage drop depth is monitored, and the current grid voltage amplitude is determined based on the grid voltage drop depth and the grid voltage amplitude.

[0062] Specifically, the preset low-voltage drop limit can be set according to actual conditions, and this application does not impose any restrictions on it. The current voltage amplitude drop depth can be determined by methods such as grid voltage measurement and status monitoring.

[0063] Step 300: Obtain the current output current of the target grid-type static var generator, and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude.

[0064] Step 400: Control the internal potential of the target grid-type static var generator to adjust to the internal potential adjustment value, so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition.

[0065] In other words, when the internal potential control of the target grid-type static var generator is adjusted to the internal potential adjustment value, the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition. The preset overcurrent capacity limit condition can be that the output current of the target grid-type static var generator is less than or equal to 3 times the rated current.

[0066] To improve the reliability of determining the current grid voltage amplitude, in one embodiment of this application, step 200, which involves determining the current grid voltage amplitude based on the grid voltage drop depth and the grid voltage amplitude, includes:

[0067] The current grid voltage amplitude U is determined using the following formula. g1 :

[0068] U g1 =(1-p)U g0

[0069] Where p represents the voltage sag depth of the power grid, Ug0 This indicates the voltage amplitude of the power grid.

[0070] To improve the reliability of determining the internal potential phasors of a grid-type static var generator, such as Figure 2 As shown, in one embodiment of this application, step 300 includes:

[0071] Step 301: Determine the grid voltage phasor based on the grid voltage amplitude and grid voltage phase.

[0072] Specifically, the grid voltage phasor U can be determined according to the following formula. g0 :

[0073] U g0 =U g0 ∠θ g0

[0074] Among them, U g0 θ represents the voltage amplitude of the power grid. m0 This indicates the phase of the grid voltage.

[0075] Step 302: Determine the internal potential phasor of the target grid-type static var generator based on the internal potential amplitude and internal potential phase.

[0076] Specifically, the potential phasor E within the grid voltage phasor can be determined using the following formula. m0 :

[0077] E m0 =E m0 ∠θ m0

[0078] Among them, E m0 θ represents the internal potential amplitude of the target grid-type static var generator. m0 This indicates the internal potential phase of the target grid-type static var generator.

[0079] Step 303: Determine the real-time value of the grid impedance of the target grid-type static var generator based on the grid voltage phasor, internal potential phasor, and current output current.

[0080] Specifically, the real-time value of the grid impedance Z can be determined according to the following formula. g :

[0081]

[0082] Where I represents the current output current of the target grid-type static var generator.

[0083] Step 304: Determine the internal potential adjustment value of the target grid-type static var generator based on the real-time value of the grid impedance, the current grid voltage amplitude, and the pre-acquired rated current.

[0084] Specifically, the internal potential adjustment value can be determined according to the following formula:

[0085] E m1 =3I m ×Z g +U g1

[0086] Among them, I m This indicates the pre-acquired rated current, which can represent the rated current of the target grid-type static var generator.

[0087] To avoid large fluctuations in reactive power support due to voltage instability during voltage fault recovery, in one embodiment of this application, the internal potential control method of the grid-type static var generator further includes: if the voltage at the grid connection point recovers to outside the preset hysteresis range, adjusting the internal potential of the target grid-type static var generator to the internal potential phasor.

[0088] Specifically, the preset hysteresis interval can be set according to the actual situation, and this application does not impose any restrictions on it.

[0089] To further illustrate this solution, this application provides an application example of an internal potential control method for a grid-type static var generator, as described in detail below:

[0090] Step 1: Obtain steady-state power grid strength impedance characteristic data.

[0091] Accurately establishing the grid strength impedance characteristics of the grid-connected SVG access point includes two parts: first, quickly obtaining the voltage amplitude at the grid connection point; and second, establishing a grid strength model of the grid-connected SVG under steady-state operation. Figure 3 This is the equivalent circuit diagram of the grid-connected SVG in this application example. Figure 3 In this context, SM represents a power unit module, N is the neutral point, and u a u b u c For the terminal voltage of each phase of the grid-type SVG, i a i b i c Let L be the current per phase of the meshed SVG, and L be the filter inductance value of the meshed SVG. Figure 4 for Figure 3 The equivalent circuit diagram of any power unit module in the diagram, where D1 to D4 are all switching transistors; during steady-state operation, the grid voltage phasor is denoted as U. g0 =Ug0 ∠θ g0 , among which, U g0 U is the grid voltage phasor. g0 Let θ be the voltage amplitude of the power grid. g0 The grid voltage phase; the grid-side equivalent impedance is represented by Z. g =R g +jX g Among them, Z g R is the equivalent impedance on the grid side. g X is the equivalent resistance on the grid side. g Z represents the grid-side equivalent reactance, where j denotes the imaginary number; g The change in represents the change in grid strength. The potential phasor within a grid-type SVG is represented as E. m0 =E m0 ∠θ m0 E m0 For the internal potential phasor of a network-type SVG, E m0 θ represents the internal potential amplitude of the grid-type static var generator. m0 The phase of the internal potential of the grid-type static var generator.

[0092] Grid impedance Z g It can be calculated using the following formula:

[0093]

[0094] When the power grid changes in real time, I SVG The above formula represents the output current of the grid-type SVG, and the real-time value of the grid impedance at the current moment can be calculated using the above formula.

[0095] Step 2: Monitor the voltage drop depth p of the power grid.

[0096] The voltage sag depth of the power grid is typically determined by methods such as power grid voltage measurement and condition monitoring, according to U. g1 =(1-p)U g0 The current grid voltage amplitude U is calculated. g1 .

[0097] Step 3: Based on the voltage and impedance values ​​of the network-type SVG, calculate the internal potential adjustment value E of the network-type SVG at different voltage drop depths. m1 .

[0098] Under the constraint of ensuring that the output current of the grid-type SVG does not exceed 3 times the rated current, I SVG No more than 3I m The calculation formula is shown in equation (2). The internal potential E of the grid-type SVG under different voltage drop faults can be obtained through equation (2). m1 The adjusted value.

[0099]

[0100] Step 4: Design the grid SVG fault voltage support to exit the hysteresis range and avoid exiting the oscillation.

[0101] To prevent reactive voltage fluctuations in grid-connected SVG near the low voltage threshold, a hysteresis range is designed. When the grid-connected voltage of the grid-connected SVG is lower than U... g Upon entering transient fault support, the internal potential of the grid-type SVG is rapidly adjusted to E. m1 When the system fault is cleared, and the system voltage returns to (U... g +ΔU + When the transient fault support is terminated, the internal potential of the grid-type SVG is adjusted to E. m0 This can prevent large fluctuations in reactive power support caused by voltage instability during voltage fault recovery. Figure 5 This is a schematic diagram of the hysteresis interval strategy used in this application example for smoothing out transient support exit of a mesh-type SVG.

[0102] like Figure 6 As shown, this application provides an application example of another method for controlling the internal potential of a grid-connected static var generator (SVG). In this application example, the method includes: obtaining the grid-connected voltage of the SVG; establishing a grid strength characteristic evaluation model for the SVG; determining the voltage regulation control parameters of the SVG; monitoring the grid voltage drop depth p; and calculating the internal potential regulation amplitude E of the SVG. m1 Adjust the internal potential of the network-type SVG to E m1 ; Check if the grid voltage has recovered. If so, determine if the grid voltage is in the hysteresis range. If not, restore the internal potential E of the grid-type SVG. q0 If the grid voltage does not recover, monitor the grid voltage drop depth p again; if the grid voltage is within the hysteresis range, maintain the internal potential E of the grid-type SVG at the time of the fault. q1 Then, determine again whether the grid voltage is within the hysteresis range.

[0103] From a software perspective, in order to achieve rapid adjustment of the internal potential of a grid-type static var generator (SVG) under transient faults, and thus ensure rapid and accurate support of the reactive current of the SVG, this application provides an embodiment of an internal potential control device for a grid-type SVG that implements all or part of the internal potential control method of the aforementioned grid-type static var generator. See [link to embodiment]. Figure 7 The internal potential control device of the grid-type static var generator specifically includes the following components:

[0104] The acquisition module 01 is used to acquire the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation.

[0105] The monitoring module 02 is used to determine that the target grid-type static var generator has experienced a transient fault if the voltage amplitude at the grid connection point is less than a preset low-voltage limit, monitor the grid voltage drop depth, and determine the current grid voltage amplitude based on the grid voltage drop depth and the grid voltage amplitude.

[0106] The first determining module 03 is used to obtain the current output current of the target grid-type static var generator and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude.

[0107] Control module 04 is used to control the internal potential of the target grid-type static var generator to be adjusted to the internal potential adjustment value, so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition.

[0108] In one embodiment, the monitoring module includes:

[0109] The monitoring unit is used to determine the current grid voltage amplitude U according to the following formula. g1 :

[0110] U g1 =(1-p)U g0

[0111] Where p represents the voltage sag depth of the power grid, U g0 This indicates the voltage amplitude of the power grid.

[0112] In one embodiment, the first determining module includes:

[0113] A voltage phasor unit is defined to determine the grid voltage phasor based on the grid voltage amplitude and grid voltage phase.

[0114] The internal potential phasor unit is determined to determine the internal potential phasor of the target grid-type static var generator based on the internal potential amplitude and internal potential phase.

[0115] The real-time impedance value determination unit is used to determine the real-time value of the grid impedance of the target grid-type static var generator based on the grid voltage phasor, internal potential phasor and current output current.

[0116] The adjustment value determination unit is used to determine the internal potential adjustment value of the target grid-type static var generator based on the real-time value of the grid impedance, the current grid voltage amplitude, and the pre-acquired rated current.

[0117] In one embodiment, the internal potential control device for the grid-type static var generator further includes:

[0118] The second determining module is used to adjust the internal potential of the target grid-type static var generator to the internal potential phasor if the voltage at the grid connection point recovers to outside the preset hysteresis range.

[0119] The embodiments of the internal potential control device for the grid-type static var generator provided in this specification can be used to execute the processing flow of the embodiments of the internal potential control method for the grid-type static var generator described above. Its functions will not be repeated here, but can be referred to the detailed description of the embodiments of the internal potential control method for the grid-type static var generator described above.

[0120] Figure 8 This is a schematic diagram of the physical structure of an electronic device provided in an embodiment of the present invention, such as... Figure 8 As shown, the electronic device includes: a memory 801, a processor 802, and a computer program stored in the memory 801 and executable on the processor 802. When the processor 802 executes the computer program, it implements the following method:

[0121] Obtain the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation.

[0122] If the voltage amplitude at the grid connection point is less than the preset low-voltage limit, it is determined that the target grid-type static var generator has experienced a transient fault. The grid voltage drop depth is monitored, and the current grid voltage amplitude is determined based on the grid voltage drop depth and the grid voltage amplitude.

[0123] Obtain the current output current of the target grid-type static var generator, and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude;

[0124] The internal potential of the target grid-type static var generator is adjusted to the internal potential adjustment value so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition.

[0125] This embodiment discloses a computer program product, which includes a computer program that, when executed by a processor, implements the following method:

[0126] Obtain the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation.

[0127] If the voltage amplitude at the grid connection point is less than the preset low-voltage limit, it is determined that the target grid-type static var generator has experienced a transient fault. The grid voltage drop depth is monitored, and the current grid voltage amplitude is determined based on the grid voltage drop depth and the grid voltage amplitude.

[0128] Obtain the current output current of the target grid-type static var generator, and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude;

[0129] The internal potential of the target grid-type static var generator is adjusted to the internal potential adjustment value so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition.

[0130] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the following method:

[0131] Obtain the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation.

[0132] If the voltage amplitude at the grid connection point is less than the preset low-voltage limit, it is determined that the target grid-type static var generator has experienced a transient fault. The grid voltage drop depth is monitored, and the current grid voltage amplitude is determined based on the grid voltage drop depth and the grid voltage amplitude.

[0133] Obtain the current output current of the target grid-type static var generator, and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude;

[0134] The internal potential of the target grid-type static var generator is adjusted to the internal potential adjustment value so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition.

[0135] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0136] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0137] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0138] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0139] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0140] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the internal electromotive force of a grid-type static var generator, characterized in that, include: Obtain the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation. If the voltage amplitude at the grid connection point is less than the preset low-voltage limit, it is determined that the target grid-type static var generator has experienced a transient fault. The grid voltage drop depth is monitored, and the current grid voltage amplitude is determined based on the grid voltage drop depth and the grid voltage amplitude. Obtain the current output current of the target grid-type static var generator, and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude; The internal potential of the target grid-type static var generator is adjusted to the internal potential adjustment value so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition. The step of determining the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current, and the current grid voltage amplitude includes: Determine the grid voltage phasor based on the grid voltage amplitude and grid voltage phase; The internal potential phasor of the target grid-type static var generator is determined based on the internal potential amplitude and internal potential phase. Based on the grid voltage phasor, internal potential phasor, and current output current, determine the real-time grid impedance value of the target grid-type static var generator; Based on the real-time value of the grid impedance, the current grid voltage amplitude, and the pre-acquired rated current, the internal potential adjustment value of the target grid-type static var generator is determined.

2. The method for controlling the internal potential of a grid-type static var generator according to claim 1, characterized in that, The step of determining the current grid voltage amplitude based on the grid voltage drop depth and the grid voltage amplitude includes: The current grid voltage amplitude is determined using the following formula. U g1 : U g1 =(1- p ) U g0 in, p Indicates the depth of voltage sag in the power grid. U g0 This indicates the voltage amplitude of the power grid.

3. The method for controlling the internal potential of a grid-type static var generator according to claim 1, characterized in that, Also includes: If the voltage at the grid connection point recovers to outside the preset hysteresis range, the internal potential of the target grid-type static var generator is adjusted to the internal potential phasor.

4. An internal potential control device for a grid-type static var generator, characterized in that, include: The acquisition module is used to acquire the impedance characteristic data and grid connection point voltage amplitude of the target grid-type static var generator. The impedance characteristic data includes: grid voltage amplitude, grid voltage phase, internal potential amplitude, and internal potential phase during steady-state operation. The monitoring module is used to determine that the target grid-type static var generator has experienced a transient fault if the voltage amplitude at the grid connection point is less than a preset low-voltage limit, monitor the grid voltage drop depth, and determine the current grid voltage amplitude based on the grid voltage drop depth and the grid voltage amplitude. The first determining module is used to obtain the current output current of the target grid-type static var generator, and determine the internal potential adjustment value of the target grid-type static var generator based on the impedance characteristic data, the current output current and the current grid voltage amplitude. The control module is used to control the internal potential of the target grid-type static var generator to be adjusted to the internal potential adjustment value so that the output current of the target grid-type static var generator meets the preset overcurrent capacity limit condition. The first determining module includes: A voltage phasor unit is defined to determine the grid voltage phasor based on the grid voltage amplitude and grid voltage phase. The internal potential phasor unit is determined to determine the internal potential phasor of the target grid-type static var generator based on the internal potential amplitude and internal potential phase. The real-time impedance value determination unit is used to determine the real-time grid impedance value of the target grid-type static var generator based on the grid voltage phasor, internal potential phasor, and current output current. The adjustment value determination unit is used to determine the internal potential adjustment value of the target grid-type static var generator based on the real-time value of the grid impedance, the current grid voltage amplitude, and the pre-acquired rated current.

5. The internal potential control device for a grid-type static var generator according to claim 4, characterized in that, The monitoring module includes: The monitoring unit is used to determine the current grid voltage amplitude according to the following formula. U g1 : U g1 =(1- p ) U g0 in, p Indicates the depth of voltage sag in the power grid. U g0 This indicates the voltage amplitude of the power grid.

6. The internal potential control device for a grid-type static var generator according to claim 4, characterized in that, Also includes: The second determining module is used to adjust the internal potential of the target grid-type static var generator to the internal potential phasor if the voltage at the grid connection point recovers to outside the preset hysteresis range.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the internal potential control method for the grid-type static var generator as described in any one of claims 1 to 3.

8. A computer-readable storage medium storing computer instructions thereon, characterized in that, When the instruction is executed by the processor, it implements the internal potential control method of the grid-type static var generator according to any one of claims 1 to 3.

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