A network-constructing new energy reactive power fast response control method and system based on a non-singular fast terminal sliding mode control

Abstract

The application relates to the technical field of new energy power system control, and relates to a grid-connected new energy reactive power fast response control method and system based on a non-singular fast terminal sliding mode control. Active power and reactive power of a power grid side are collected to input a virtual synchronous machine control, voltage reference values and phase angle reference values are calculated, the voltage reference values and the phase angle reference values output by the virtual synchronous machine control are combined into three-phase voltage, and the output current and voltage of an inverter are converted into d-axis current and voltage and q-axis current and voltage through coordinate conversion; the d-axis current and the q-axis current are input into adaptive virtual impedance control to obtain d-axis reference voltage and q-axis reference voltage; voltage and current double-loop control is carried out according to the d-axis reference voltage and the q-axis reference voltage to generate SVPWM signals. The application realizes fast, low overshoot and zero static error reactive step response under a weak grid condition.

Description

Technical Field

[0001] This application relates to the field of new energy power system control technology, and to a fast response control method and system for grid-type new energy reactive power based on non-singular fast terminal sliding mode control. Background Technology

[0002] Currently, grid-based renewable energy control methods, by simulating the operating characteristics of synchronous generators, can provide the system with virtual inertia, damping, and rapid frequency / voltage support. Traditional reactive power regulation methods for grid-based renewable energy mainly include droop control and PI control. Droop control is essentially a first-order control system; by increasing the droop coefficient, it can increase the reactive power's sensitivity to voltage, but this leads to increased steady-state deviation and even reduces the stability margin of the control system. While PI control is a second-order system, its fixed parameter design presents a trade-off between response speed and stability. Furthermore, during dynamic regulation, active-reactive coupling causes reactive power regulation to induce active power fluctuations.

[0003] While some improvement methods, such as introducing integral elements or increasing control gain, can eliminate reactive steady-state errors, they may induce dynamic overshoot or oscillations, affecting reactive power regulation and system stability. Therefore, achieving fast and accurate reactive power tracking response in grid-connected renewable energy systems while simultaneously implementing active-reactive power decoupling control is a significant technical challenge that urgently needs to be overcome. To address this, this application designs a fast response control method for reactive power in grid-connected renewable energy systems based on non-singular fast terminal sliding mode control (NFTSM). It replaces the traditional PI regulator by introducing a non-singular fast terminal sliding mode control (NFTSM) algorithm from finite-time control into the reactive power outer loop. This algorithm has the advantages of fast convergence and strong robustness, significantly reducing voltage deviation and improving dynamic response. Furthermore, an adaptive virtual impedance method is designed to weaken the cross-influence between active and reactive power and improve dynamic controllability under weak grid conditions.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0006] This disclosure provides a fast response control method and system for grid-connected renewable energy reactive power based on non-singular fast terminal sliding mode control (NFTSM). The method introduces a non-singular fast terminal sliding mode control (NFTSM) algorithm with fast convergence and strong robustness into the reactive power outer loop to replace the traditional PI regulator, thereby significantly reducing voltage deviation and improving dynamic response. Furthermore, an adaptive virtual impedance method is designed to weaken the cross-influence between active and reactive power and improve dynamic controllability under weak grid conditions.

[0007] In some embodiments, the method includes: acquiring active and reactive power from the grid side and inputting them into a virtual synchronous machine control, calculating voltage reference values ​​and phase angle reference values; in the virtual synchronous machine control, the PI regulator is replaced with a non-singular fast terminal sliding mode control module;

[0008] The active and reactive power from the power grid side are collected and input into the virtual synchronous machine control to calculate the voltage reference value and phase angle reference value; in the virtual synchronous machine control, the PI regulator is replaced by a non-singular fast terminal sliding mode control module;

[0009] The voltage reference value and phase angle reference value of the virtual synchronous machine control output are combined into three-phase voltage, and the inverter output current and three-phase voltage are converted into d-axis current and voltage via coordinates;

[0010] The d-axis current and q-axis current are input into the adaptive virtual impedance control to obtain new d-axis reference voltage and q-axis reference voltage. The adaptive virtual impedance control dynamically adjusts the reactance of the line.

[0011] Based on the new d-axis reference voltage and q-axis reference voltage, voltage and current dual closed-loop control is performed to generate SVPWM signals.

[0012] Preferably, the voltage reference value of the reactive power control loop controlled by the virtual synchronous machine is calculated as follows:

[0013] The reactive power error is obtained by subtracting the reactive power reference value and the actual reactive power value, and the reactive power error is then filtered.

[0014] The filtered reactive power error is input into the non-singular fast terminal sliding mode control module, which outputs a voltage reference command containing an initial voltage control quantity, a continuous feedforward compensation term, and a step feedforward voltage compensation term; the voltage reference command is related to the initial value of the voltage amplitude. The values ​​are added together to obtain the voltage reference value output by the reactive power control loop.

[0015] Preferably, the specific method for the output voltage reference command of the non-singular fast terminal sliding mode control module is as follows:

[0016] Constructing a non-singular terminal sliding surface based on the reactive power error after filtering :

[0017] ,

[0018] ,

[0019] in, The sliding surface coefficient, It introduces the time scale of the differential term. For reactive power error, The first derivative of the power error. For time, This is a reference value for reactive power. This is the measured value of reactive power;

[0020] Based on the non-singular terminal sliding surface, the initial voltage control quantity is calculated using a sliding mode control law that includes a combination of power terms and linear terms:

[0021] ,

[0022] in, The sliding mode index, For feedback gain, It is a nonlinear reaching term. As an equivalent control item, It is a symbolic function.

[0023] The continuous feedforward compensation term is calculated based on the reactive power error, and the change in the reactive power reference value is detected simultaneously. When a step change occurs, the step feedforward voltage compensation term is calculated based on the increment of the reactive power reference value.

[0024] The initial voltage control quantity, the continuous feedforward compensation term, and the step feedforward voltage compensation term are added together to obtain the final voltage reference command.

[0025] Preferably, the continuous feedforward compensation term is:

[0026] ,

[0027] in, For continuous feedforward coefficients, It is the power frequency angular frequency. , and These are the filter inductor, the grid-side inductor, and the virtual inductor, respectively. For the previous moment's angle, This is the grid voltage.

[0028] Preferably, the voltage compensation term of the step feedforward is:

[0029] ,

[0030] ,

[0031] ,

[0032] ,

[0033] in, For step feedforward coefficients, and These represent the minimum and maximum feedforward gains, respectively. To normalize the reference step size, For shape adjustment index, For the incremental reactive power reference, This refers to the approximately linear gain of the inverter's reactive power output to the change in output voltage. This is the reference value for reactive power at the previous moment.

[0034] Preferably, the parameter tuning method for the non-singular fast terminal sliding mode control module is as follows:

[0035] Feedback gain Linear selection Approximating the small error region as a linear exponential decay, take... ;

[0036] Sliding mode index Take 0.5;

[0037] Sliding surface coefficient : Take 1, Take a value of 0.3 to 0.7;

[0038] Continuous feedforward coefficients Step feedforward coefficient : Take a value of 0.8 to 1.0. Take a value of 0.5~0.7; Take a value of 1.0 to 1.2 for the shape adjustment index. Take a value of 0.6 to 1.2.

[0039] Preferably, the adaptive virtual impedance control dynamically adjusts the reactance of the line as follows:

[0040] Based on the voltage reference command, output active power, and system inherent impedance parameters of the previous control cycle, calculate the equivalent reactance of the previous cycle. :

[0041] ,

[0042] in, It is the power frequency angular frequency. For filtering inductors, For line inductance, For virtual inductance;

[0043] Calculate the target equivalent reactance With the target virtual inductance :

[0044] ,

[0045] ,

[0046] in, This is the voltage-reactance scaling factor;

[0047] Calculate the equivalent reactance for the current cycle based on the target virtual inductance. :

[0048] .

[0049] In some embodiments, the grid-based renewable energy reactive power fast response control system based on non-singular fast terminal sliding mode control includes:

[0050] Information acquisition module: Collects active and reactive power from the power grid side and inputs it into the virtual synchronous machine control module;

[0051] Virtual synchronous machine control module: calculates voltage reference value and phase angle reference value; in the virtual synchronous machine control, the PI regulator is replaced with a non-singular fast terminal sliding mode control module;

[0052] Current conversion module: Combines the voltage reference value and phase angle reference value output by the virtual synchronous machine control to form a three-phase voltage. Inverter output current With three-phase voltage The coordinate system is converted to d-axis and q-axis current and voltage.

[0053] Adaptive Virtual Impedance Control Module: Inputs the d-axis current and q-axis current into the adaptive virtual impedance control module to obtain... and The adaptive virtual impedance control dynamically adjusts the reactance of the line;

[0054] Dual-loop control module: based on and Perform voltage and current dual closed-loop control to generate SVPWM signal.

[0055] In some embodiments, the grid-based renewable energy reactive power fast response control device based on non-singular fast terminal sliding mode control includes a processor and a memory storing program instructions. The processor is configured to execute the grid-based renewable energy reactive power fast response control method based on non-singular fast terminal sliding mode control when running the program instructions.

[0056] In some embodiments, the computer-readable storage medium stores a computer program that, when executed by a processor, implements the fast response control method for reactive power of grid-connected new energy sources based on non-singular fast terminal sliding mode control.

[0057] The present disclosure provides a fast response control method and system for grid-connected renewable energy reactive power based on non-singular fast terminal sliding mode control, which can achieve the following technical effects:

[0058] This invention combines NFTSM reactive power outer loop control with adaptive virtual reactance design, achieving fast, low overshoot, and zero steady-state error reactive power step response under weak network conditions. NFTSM constructs a sliding mode surface by applying error low-pass and filter derivatives, and approaches it with a power term plus a linear term. Combined with continuous feedforward and step feedforward, it exhibits finite-time convergence and strong robustness, significantly outperforming the dynamic performance and jitter resistance of traditional PI outer loops under model mismatch and external disturbances. Simultaneously, the adaptive virtual reactance scales the equivalent reactance online according to the voltage command and operating point, maintaining... Approximately constant, making the reactive small-signal gain It does not drift with different reactive power targets, ensuring the effectiveness of continuous / step feedforward under all operating conditions; and it suppresses PQ coupling, reducing active power disturbances under transient conditions.

[0059] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0060] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0061] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0062] Figure 2 The block diagram for the improved post-network VSG control strategy;

[0063] Figure 3 This is a power response curve diagram for traditional VSG control.

[0064] Figure 4 Power response curves for a novel finite-time control + virtual impedance VSG control method;

[0065] Figure 5 A schematic diagram of the device structure is provided for this embodiment. Detailed Implementation

[0066] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0067] The terms "first," "second," etc., used in the specification and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0068] Unless otherwise stated, the term "multiple" means two or more.

[0069] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0070] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0071] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0072] Example 1

[0073] like Figures 1-2 As shown, a fast response control method for reactive power in grid-connected renewable energy based on non-singular fast terminal sliding mode control is proposed. This method introduces non-singular fast terminal sliding mode control to replace the voltage droop and integral components in the original reactive-voltage control outer loop, improving the reactive power response speed and accuracy, based on the traditional VSG control architecture for grid-connected renewable energy. Simultaneously, adaptive virtual impedance is employed to achieve fast and accurate reactive power response during transient processes while maintaining active power essentially constant.

[0074] Specifically, the method includes:

[0075] S1: Collect the active and reactive power from the grid side and input them into the virtual synchronous machine control to calculate the voltage reference value and phase angle reference value; in the virtual synchronous machine control, the PI regulator is replaced with a non-singular fast terminal sliding mode control module;

[0076] S2: The voltage reference value output by the virtual synchronizer control. and phase angle reference value Synthetic three-phase voltage Inverter output current With three-phase voltage The coordinate system is converted to d-axis and q-axis current and voltage.

[0077] S3: Input the d-axis current and q-axis current into the adaptive virtual impedance control to obtain a new d-axis reference voltage. and q-axis reference voltage The adaptive virtual impedance control dynamically adjusts the reactance of the line;

[0078] S4: Based on the new d-axis reference voltage and q-axis reference voltage Perform voltage and current dual closed-loop control to generate SVPWM signal.

[0079] As a refinement of the above embodiments, the voltage regulation capability of a traditional VSG is achieved through reactive power excitation ring control, as shown in the following formula:

[0080] ,

[0081] in, and These are the VSG reactive inertia coefficient and reactive droop coefficient, respectively, which simulate the voltage regulation and droop characteristics of a synchronous generator. This is a reference value for reactive power. This is the measured value of reactive power. This is the VSG reference voltage command value. This is the output voltage value of the VSG.

[0082] However, fixed droop coefficients suffer from slow dynamic response and poor steady-state regulation accuracy. To improve the speed and accuracy of reactive power voltage regulation, this invention introduces the Non-Singular Fast Terminal Sliding Mode Control (NFTSM) algorithm from finite-time control into the reactive power outer loop to replace the traditional PI regulator. This sliding mode variable structure control has the advantages of fast convergence and strong robustness, which can significantly reduce voltage deviation and improve dynamic response.

[0083] Specifically, the calculation method for the reactive power control loop voltage reference value of the virtual synchronous machine is as follows:

[0084] S101: The reactive power error is obtained by subtracting the reactive power reference value and the measured reactive power value, and the reactive power error is... Perform filtering:

[0085] ,

[0086] To suppress noise interference, error All results are after low-pass filtering.

[0087] S102: Input the filtered reactive power error into the non-singular fast terminal sliding mode control module, and output a voltage reference command including an initial voltage control quantity, a continuous feedforward compensation term, and a step feedforward voltage compensation term; the voltage reference command is related to the initial value of the voltage amplitude. The values ​​are added together to obtain the voltage reference value output by the reactive power control loop.

[0088] Specifically, the output voltage reference command of the non-singular fast terminal sliding mode control module is implemented as follows:

[0089] S1021: To balance error and rate of change, a combined sliding mode variable (sliding surface) is introduced; a non-singular terminal sliding surface is constructed based on the reactive power error after filtering. :

[0090] ,

[0091] ,

[0092] in, The sliding surface coefficient, It introduces the time scale of the differential term. For reactive power error, The first derivative of the power error. For time, This is a reference value for reactive power. The above formula represents the measured reactive power value, where the formula describes a non-singular terminal sliding surface. The time includes the error derivative, which is beneficial for rapid response and reducing steady-state error.

[0093] S1022: Based on the non-singular terminal sliding surface, the initial voltage control quantity is calculated using a sliding mode control law that includes a combination of power terms and linear terms:

[0094] ,

[0095] in, The sliding mode index, For feedback gain, As a nonlinear reaching term, it achieves finite-time convergence of the error. As an equivalent control term, it improves the system's damping and steady-state accuracy. For sign functions. When When the value is large, the nonlinear term dominates, enabling rapid approximation to the sliding surface; as the surface approaches, the linear term dominates, leading to asymptotic stability. Therefore, combining these two terms can reduce sliding chattering and eliminate steady-state errors while ensuring speed.

[0096] S1023: Calculate the continuous feedforward compensation term based on the reactive power error, and simultaneously detect the change in the reactive power reference value. When a step change occurs, calculate the step feedforward voltage compensation term based on the increment of the reactive power reference value.

[0097] (1) When the reactive power command changes significantly, in order to reduce the pressure of sliding mode regulation and thus accelerate convergence and reduce the initial impact, a continuous feedforward + step feedforward compensation method is added to the controller. The voltage compensation term of the continuous feedforward is:

[0098] ,

[0099] definition This refers to the approximately linear gain of the inverter's reactive power output to the change in output voltage. For continuous feedforward coefficients, , and These are the filter inductor, the grid-side inductor, and the virtual inductor, respectively. For the previous moment's angle, This refers to the grid voltage. When a persistent reactive power deviation occurs, continuous feedforward compensation enables the controller to immediately apply a voltage correction of the corresponding magnitude.

[0100] (2) When the reactive power reference experiences a step change, the increment of the reactive power reference is calculated as follows:

[0101] ,

[0102] in, This is the reference value for reactive power at the previous moment.

[0103] The voltage compensation term for step feedforward is:

[0104] ,

[0105] ,

[0106] ,

[0107] in, For step feedforward coefficients, and These represent the minimum and maximum feedforward gains, respectively. To normalize the reference step size, For shape adjustment index, This is the approximately linear gain of the inverter's reactive power output to the change in output voltage.

[0108] Step feedforward ensures that the voltage reference can quickly jump to near the new equilibrium value when the command changes abruptly, shortening the adjustment process time.

[0109] S1024: Add the initial voltage control quantity, the continuous feedforward compensation term, and the step feedforward voltage compensation term to obtain the final voltage reference command:

[0110] .

[0111] Parameter tuning:

[0112] Feedback gain This determines the system's convergence speed and steady-state error. Higher gain results in faster response but also greater chattering; linear selection is recommended. To ensure that the small error region approximates linear exponential decay, then take... , A larger size can introduce high-frequency jitter.

[0113] index Generally, 0.5 is taken (a common value for terminal sliding mode) to ensure a trade-off between finite-time convergence and smooth response. The smaller the value, the stronger the nonlinear approach effect, and the faster the initial convergence, but the chattering may increase in the steady state. If necessary, it can be adjusted in the range of 0.3 to 0.7.

[0114] Sliding surface coefficient : Typically, a value of 1 is used to directly utilize the entire error. Determine the weight of the error differential term. The value should be between 0.3 and 0.7. When the noise level is high, the value should be lower to reduce the amplification effect of item D. The value should be similar to the magnitude of the current inner loop or reactive power dynamic characteristics, but should not be too large to avoid over-prediction.

[0115] Feedforward coefficient To avoid overshoot caused by repeated feedforward when reactive power changes, this invention employs the feedforward quota law. Use a value of 0.8 to 1.0; For small to medium step jumps, overshoot can be limited to 0.5 to 0.7. For large step transitions, a near-one-step capability is provided, with a value of 1.0 to 1.2. Shape adjustment index. Take a value of 0.6 to 1.2. The step weight increases faster. The continuous feedforward channel is responsible for smoothing out reading errors, while the step feedforward channel is responsible for instantaneous compensation for sudden changes in reading settings.

[0116] In summary, the NFTSM outer-loop control combines the fast sliding mode control and the steady-state accuracy of PI control, and incorporates improvements in the feedforward stage, enabling rapid and accurate tracking of reactive power commands. Compared to traditional fixed droop control, sliding mode control significantly improves dynamic performance and robustness.

[0117] As a refinement of the above embodiments, in order to ensure the stability of active power while adjusting reactive power, the present invention adopts adaptive virtual impedance control to dynamically adjust the impedance value of the line and reduce active-reactive coupling.

[0118] In VSG grid connection, the equivalent is "internal potential". "Through equivalent reactance" With grid voltage When connected (ignoring resistance), the standard power relationship is:

[0119] ,

[0120] When tracking new And change At that time, if Unchanged, active power Then it will follow It drifts due to changes in [something]. To ensure that the active power remains constant, it is necessary to [something]. .in and These are the active power values ​​for the next clock cycle and the current clock cycle, respectively. Therefore, the adaptive virtual impedance control dynamically adjusts the line's reactance as follows:

[0121] S301: Calculate the equivalent reactance of the previous control cycle based on the voltage reference command, output active power, and system inherent impedance parameters. :

[0122] ,

[0123] in, It is the power frequency angular frequency. For filtering inductors, For line inductance, For virtual inductance;

[0124] S302: Calculate the target equivalent reactance With the target virtual inductance To ensure that the reactive power-voltage characteristics remain consistent across different voltage operating points, and to balance the active power and power angle during transient processes... The basic requirements remain unchanged, and the following conditions must be met:

[0125] ,

[0126] but It needs to remain constant; therefore, the target equivalent reactance and the target virtual inductance are respectively:

[0127] ,

[0128] ,

[0129] ,

[0130] in, This is the voltage-reactance scaling factor;

[0131] S303: Calculate the equivalent reactance for the current cycle based on the target virtual inductance. :

[0132] .

[0133] The adaptive virtual impedance control obtains a new d-axis reference voltage. and q-axis reference voltage The specific method is as follows:

[0134] ,

[0135] in, The d-axis component is the original voltage reference. The q-axis component is the reference voltage. For virtual resistance, The inverter outputs d-axis current. This provides the q-axis current output by the inverter.

[0136] In summary, adaptive virtual impedance ensures performance under different reactive power variation scenarios. The constancy of the constant effectively weakens the transient process of reactive step jump. The coupling ensures the accuracy of the NFTSM outer loop control feedforward compensation, thereby achieving the goal of fast and accurate reactive step tracking and maintaining a basically constant active power during transients.

[0137] As a refinement of the above embodiments, other aspects of the control method (see reference) Figure 2 )as follows:

[0138] Active power control loop

[0139] The active power control loop of this application is the same as the traditional VSG active power-frequency control loop, that is, it constructs the rotor mechanical equation to simulate the inertial response and damping characteristics of the synchronous machine rotor, and the specific formula is as follows:

[0140] ,

[0141] in, and These are the moment of inertia and the damping coefficient, respectively. and These are the active power reference value and the active power output value, respectively.

[0142] Voltage and current controlled dual loop

[0143] The voltage-current dual-loop control in this application is the same as the traditional VSG dual-loop structure. Through the hierarchical coordination of the outer voltage loop and the inner current loop, it achieves precise adjustment of the inverter output performance.

[0144] Effect: such as Figure 3 and Figure 4 As shown, traditional control methods have slow reactive power response speed and overshoot, and active power fluctuates greatly during the adjustment process; while the method designed in this application can achieve fast and accurate reactive power response during transient processes while keeping active power basically stable.

[0145] Example 2

[0146] Combination Figure 5 As shown, this disclosure provides a fast response control device 300 for grid-connected renewable energy reactive power based on non-singular fast terminal sliding mode control, including a processor 304 and a memory 301. Optionally, the device may further include a communication interface 302 and a bus 303. The processor 304, communication interface 302, and memory 301 can communicate with each other via the bus 303. The communication interface 302 can be used for information transmission. The processor 304 can call logical instructions in the memory 301 to execute the fast response control method for grid-connected renewable energy reactive power based on non-singular fast terminal sliding mode control described in the above embodiment.

[0147] Furthermore, the logic instructions in the aforementioned memory 301 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0148] The memory 301, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 304 executes functional applications and data processing by running the program instructions / modules stored in the memory 301, thereby realizing the fast response control method for grid-connected new energy reactive power based on non-singular fast terminal sliding mode control in the above embodiments.

[0149] The memory 301 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 301 may include high-speed random access memory and may also include non-volatile memory.

[0150] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to execute the above-described fast response control method for reactive power of grid-connected new energy sources based on non-singular fast terminal sliding mode control.

[0151] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0152] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code. It can also be a transient storage medium.

[0153] The foregoing description and accompanying drawings fully illustrate embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. As used in the description of the embodiments, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used herein means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the terms “comprise” and its variations “comprises” and / or “comprising” refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Unless otherwise specified, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on its differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, then the relevant parts can be referred to the description of the method section.

[0154] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0155] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection shown or discussed between each other may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. In addition, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0156] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A fast response control method for reactive power of grid-connected new energy sources based on non-singular fast terminal sliding mode control, characterized in that, Includes the following steps: The active and reactive power from the power grid side are collected and input into the virtual synchronous machine control to calculate the voltage reference value and phase angle reference value; in the virtual synchronous machine control, the PI regulator is replaced by a non-singular fast terminal sliding mode control module; The voltage reference value and phase angle reference value of the virtual synchronous machine control output are combined into three-phase voltage, and the inverter output current and three-phase voltage are converted into d-axis current and voltage via coordinates; The d-axis current and q-axis current are input into the adaptive virtual impedance control to obtain the d-axis reference voltage and q-axis reference voltage. The adaptive virtual impedance control dynamically adjusts the reactance of the line. Based on the d-axis reference voltage and the q-axis reference voltage, voltage and current dual closed-loop control is performed to generate SVPWM signal; The calculation method for the reactive power control loop voltage reference value controlled by the virtual synchronous machine is as follows: The reactive power error is obtained by subtracting the reactive power reference value and the actual reactive power value, and the reactive power error is then filtered. The filtered reactive power error is input into the non-singular fast terminal sliding mode control module, which outputs a voltage reference command containing an initial voltage control quantity, a continuous feedforward compensation term, and a step feedforward voltage compensation term; the voltage reference command is related to the initial value of the voltage amplitude. The sums are used to obtain the voltage reference value output by the reactive power control loop; The specific method for outputting the voltage reference command of the non-singular fast terminal sliding mode control module is as follows: Constructing a non-singular terminal sliding surface based on the reactive power error after filtering : ， ， in, The sliding surface coefficient, It introduces the time scale of the differential term. For reactive power error, The first derivative of the power error. For time, This is a reference value for reactive power. This is the measured value of reactive power; Based on the non-singular terminal sliding surface, the initial voltage control quantity is calculated using a sliding mode control law that includes a combination of power terms and linear terms: ， in, The sliding mode index, For feedback gain, It is a nonlinear reaching term. As an equivalent control item, It is a symbolic function; The continuous feedforward compensation term is calculated based on the reactive power error, and the change in the reactive power reference value is detected simultaneously. When a step change occurs, the step feedforward voltage compensation term is calculated based on the increment of the reactive power reference value. The initial voltage control quantity, the continuous feedforward compensation term, and the step feedforward voltage compensation term are added together to obtain the final voltage reference command. The adaptive virtual impedance control dynamically adjusts the line's reactance as follows: Based on the voltage reference command, output active power, and system inherent impedance parameters of the previous control cycle, calculate the equivalent reactance of the previous cycle. : ， in, It is the power frequency angular frequency. For filtering inductors, For line inductance, For virtual inductance; Calculate the target equivalent reactance With the target virtual inductance : ， ， in, This is the voltage-reactance scaling factor; Calculate the equivalent reactance for the current cycle based on the target virtual inductance. : 。 2. The fast response control method for reactive power of grid-connected new energy sources based on non-singular fast terminal sliding mode control according to claim 1, characterized in that, The continuous feedforward compensation term is: ， in, For continuous feedforward coefficients, It is the power frequency angular frequency. , and These are the filter inductor, the grid-side inductor, and the virtual inductor, respectively. For the previous moment's angle, This is the grid voltage.

3. The fast response control method for reactive power of grid-connected new energy sources based on non-singular fast terminal sliding mode control according to claim 2, characterized in that, The voltage compensation term for the step feedforward is: ， ， ， ， in, For step feedforward coefficients, and These represent the minimum and maximum feedforward gains, respectively. To normalize the reference step size, For shape adjustment index, For the incremental reactive power reference, This refers to the approximately linear gain of the inverter's reactive power output to the change in output voltage. This is the reference value for reactive power at the previous moment.

4. The fast response control method for reactive power of grid-connected new energy sources based on non-singular fast terminal sliding mode control according to claim 3, characterized in that, The parameter tuning method for the non-singular fast terminal sliding mode control module is as follows: Feedback gain Linear selection Approximating the small error region as a linear exponential decay, take... ; Sliding mode index Take 0.5; Sliding surface coefficient : Take 1, Take a value of 0.3 to 0.7; Continuous feedforward coefficients Step feedforward coefficient : Take a value of 0.8 to 1.

0. Take a value of 0.5 to 0.7; Take a value of 1.0 to 1.2 for the shape adjustment index. Take a value of 0.6 to 1.

2.

5. A grid-based new energy reactive power fast response control system based on non-singular fast terminal sliding mode control using the method described in any one of claims 1-4, characterized in that, include: Information acquisition module: Collects active and reactive power from the power grid side and inputs it into the virtual synchronous machine control module; Virtual synchronous machine control module: calculates voltage reference value and phase angle reference value; the PI regulator in the virtual synchronous machine control module is replaced with a non-singular fast terminal sliding mode control module; Current conversion module: Combines the voltage reference value and phase angle reference value output by the virtual synchronous machine control to form a three-phase voltage. Inverter output current With three-phase voltage The coordinate system is converted to d-axis and q-axis current and voltage. Adaptive Virtual Impedance Control Module: Inputs the d-axis current and q-axis current into the adaptive virtual impedance control module to obtain... and The adaptive virtual impedance control dynamically adjusts the reactance of the line; Dual-loop control module: based on and Perform voltage and current dual closed-loop control to generate SVPWM signal.

6. A grid-based renewable energy reactive power fast response control device based on non-singular fast terminal sliding mode control, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to execute, when running the program instructions, the fast response control method for reactive power of grid-connected new energy sources based on non-singular fast terminal sliding mode control as described in any one of claims 1-4.

7. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed by a processor, implements the fast response control method for grid-type renewable energy reactive power based on non-singular fast terminal sliding mode control as described in any of claims 1-4 above.

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