Method, system and equipment for synchronous control of hybrid networking and medium

Abstract

The invention discloses a method, a system, equipment and a medium for synchronous control of hybrid networking, and belongs to the technical field of transient stability control. The method comprises the following steps: determining an output duty ratio component Dabc of a network controller in the hybrid network, and determining an output duty ratio component delta Dabc of a q-axis voltage controller in the hybrid network; performing superposition processing on the Dabc and the delta Dabc to obtain the duty ratio dac of the fan converter in the hybrid network; based on the dabc, calculating to obtain voltage positive and negative sequence components to be injected into the q-axis voltage controller; performing synchronous control on the hybrid network construction according to the voltage positive and negative sequence components; wherein the fan converter is connected into a power grid through an L filter to form a grid construction controller, and a q-axis voltage controller is additionally arranged in the fan converter to form a hybrid grid construction. According to the invention, the transient stability of the power grid is improved by performing synchronous control on the hybrid network construction.

Description

Technical Field

[0001] The present invention relates to the technical field of transient stability control, and more specifically, to a method, system, device and medium for hybrid network synchronization control. Background Art

[0002] Compared with the low inertia of grid-following control, grid-building control technology can actively establish a voltage with inertia by simulating the rotor motion equation of the traditional synchronous machine. It can autonomously and quickly build the system voltage in a weak power grid, compensate for the lack of inherent inertial damping characteristics of the system, and provide reliable voltage and frequency support for the system.

[0003] At the same time, precisely because the networking control technology simulates the characteristics of traditional synchronous machines, it will encounter various stability problems existing in synchronous machines.

[0004] If a new energy unit using grid control suffers transient instability after a fault disturbance, it is very likely to trigger the unit's fault-crossing control protection action, affecting the reliable operation of the unit and even causing the new energy to go offline. Therefore, the transient stability performance of grid-type control under power grid faults is a key issue restricting its operation.

[0005] Existing results mainly focus on the transient synchronization stability problem of network control strategies under symmetrical faults, but there is little in-depth research on the transient synchronization stability characteristics under asymmetrical AC faults. Summary of the invention

[0006] In view of the above problems, the present invention proposes a method for hybrid networking synchronization control, comprising:

[0007] Determine the output duty cycle component D of the networking controller in the hybrid networking abc , and determine the output duty cycle component ΔD of the q-axis voltage controller in the hybrid network abc ;

[0008] For the D abc and ΔD abc Perform superposition processing to obtain the duty cycle d of the wind turbine converter in the hybrid network abc ;

[0009] Based on the d abc , calculate the positive and negative sequence components of the voltage to be injected into the q-axis voltage controller;

[0010] Synchronously controlling the hybrid network according to the positive and negative sequence components of the voltage;

[0011] The wind turbine converter is connected to the power grid through an L filter to form a grid controller, and a q-axis voltage controller is added to the wind turbine converter to form a hybrid grid.

[0012] Optional, based on the d abc , the voltage positive and negative sequence components to be injected into the q-axis voltage controller are calculated, including:

[0013] Based on the d abc , determining a q-axis voltage component, and calculating a negative sequence current based on the q-axis voltage component;

[0014] Determining voltage positive and negative sequence components to be injected into a q-axis voltage controller based on the negative sequence current and a negative sequence current threshold of the negative sequence current;

[0015] The negative sequence current does not exceed a negative sequence current threshold.

[0016] Optionally, based on the q-axis voltage component, a calculation formula for the negative sequence current is calculated as follows:

[0017]

[0018] Among them, U qp and U qn is the q-axis voltage component, I n is the negative sequence current, U g is the grid-side voltage, k1, k2 and k3 are voltage action coefficients respectively.

[0019] Optionally, the hybrid grid is synchronously controlled by using virtual synchronous generator technology and the voltage positive and negative sequence components, including:

[0020] The virtual synchronous generator technology is used to control the grid controller in the hybrid grid, and the q-axis voltage controller is synchronously controlled by the voltage positive and negative sequence components.

[0021] Optionally, controlling a network controller in a hybrid network by using the virtual synchronous generator technology includes:

[0022] The network controller is controlled using the P-θ and Qu control strategies to output the target control voltage.

[0023] On the other hand, the present invention also proposes a system for hybrid networking synchronization control, comprising:

[0024] The first calculation unit is used to determine the output duty cycle component D of the networking controller in the hybrid networking abc , and determine the output duty cycle component ΔD of the q-axis voltage controller in the hybrid network abc ;

[0025] The second calculation unit is used to calculate the D abc and ΔD abc Perform superposition processing to obtain the duty cycle d of the wind turbine converter in the hybrid networkabc ;

[0026] The third calculating unit is used for abc , calculate the positive and negative sequence components of the voltage to be injected into the q-axis voltage controller;

[0027] A synchronization control unit, used for performing synchronization control on the hybrid network according to the positive and negative sequence components of the voltage;

[0028] The wind turbine converter is connected to the power grid through an L filter to form a grid controller, and a q-axis voltage controller is added to the wind turbine converter to form a hybrid grid.

[0029] Optional, based on the d abc , the voltage positive and negative sequence components to be injected into the q-axis voltage controller are calculated, including:

[0030] Based on the d abc , determining a q-axis voltage component, and calculating a negative sequence current based on the q-axis voltage component;

[0031] Determining voltage positive and negative sequence components to be injected into a q-axis voltage controller based on the negative sequence current and a negative sequence current threshold of the negative sequence current;

[0032] The negative sequence current does not exceed a negative sequence current threshold.

[0033] Optionally, based on the q-axis voltage component, a calculation formula for the negative sequence current is calculated as follows:

[0034]

[0035] Among them, U qp and U qn is the q-axis voltage component, I n is the negative sequence current, U g is the grid-side voltage, k1, k2 and k3 are voltage action coefficients respectively.

[0036] Optionally, the hybrid grid is synchronously controlled by using virtual synchronous generator technology and the voltage positive and negative sequence components, including:

[0037] The virtual synchronous generator technology is used to control the grid controller in the hybrid grid, and the q-axis voltage controller is synchronously controlled by the voltage positive and negative sequence components.

[0038] Optionally, controlling a network controller in a hybrid network by using the virtual synchronous generator technology includes:

[0039] The network controller is controlled using the P-θ and Qu control strategies to output the target control voltage.

[0040] In yet another aspect, the present invention further provides a computing device, comprising: one or more processors;

[0041] a processor for executing one or more programs;

[0042] When the one or more programs are executed by the one or more processors, the above-described method is implemented.

[0043] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method described above is implemented.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The present invention provides a method for hybrid networking synchronization control, comprising: determining an output duty cycle component D of a networking controller in the hybrid networking abc , and determine the output duty cycle component ΔD of the q-axis voltage controller in the hybrid network abc ; for the D abc and ΔD abc Perform superposition processing to obtain the duty cycle d of the wind turbine converter in the hybrid network abc Based on the d abc , calculate the voltage positive and negative sequence components to be injected into the q-axis voltage controller; according to the voltage positive and negative sequence components, perform synchronous control on the hybrid network; wherein, the wind turbine converter is incorporated into the power grid through an L filter to form a network controller, and a q-axis voltage controller is added to the wind turbine converter to form a hybrid network. The present invention improves the transient stability of the power grid by synchronously controlling the hybrid network. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a flow chart of the method of the present invention;

[0047] Figure 2 Schematic diagram of synchronous control of the method of the present invention;

[0048] Figure 3 A schematic diagram of hybrid synchronous control with positive and negative sequence decoupling in the method of the present invention;

[0049] Figure 4 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0050] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0051] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0052] Embodiment 1:

[0053] The present invention proposes a method for hybrid network synchronization control, such as Figure 1 As shown, including:

[0054] Step 1: Determine the output duty cycle component D of the network controller in the hybrid network abc , and determine the output duty cycle component ΔD of the q-axis voltage controller in the hybrid network abc ;

[0055] Step 2: abc and ΔD abc Perform superposition processing to obtain the duty cycle d of the wind turbine converter in the hybrid network abc ;

[0056] Step 3: Based on the d abc , calculate the positive and negative sequence components of the voltage to be injected into the q-axis voltage controller;

[0057] Step 4: Synchronously controlling the hybrid network according to the positive and negative sequence components of the voltage;

[0058] The wind turbine converter is connected to the power grid through an L filter to form a grid controller, and a q-axis voltage controller is added to the wind turbine converter to form a hybrid grid.

[0059] Among them, based on the d abc , the voltage positive and negative sequence components to be injected into the q-axis voltage controller are calculated, including:

[0060] Based on the d abc , determining a q-axis voltage component, and calculating a negative sequence current based on the q-axis voltage component;

[0061] Determining voltage positive and negative sequence components to be injected into a q-axis voltage controller based on the negative sequence current and a negative sequence current threshold of the negative sequence current;

[0062] The negative sequence current does not exceed a negative sequence current threshold.

[0063] Wherein, based on the q-axis voltage component, the calculation formula for the negative sequence current is calculated as follows:

[0064]

[0065] Among them, U qp and U qn is the q-axis voltage component, I n is the negative sequence current, U g is the grid-side voltage, k1, k2 and k3 are voltage action coefficients respectively.

[0066] The hybrid grid is synchronously controlled by using virtual synchronous generator technology and the positive and negative sequence components of the voltage, including:

[0067] The virtual synchronous generator technology is used to control the grid controller in the hybrid grid, and the q-axis voltage controller is synchronously controlled by the voltage positive and negative sequence components.

[0068] The virtual synchronous generator technology is used to control the network controller in the hybrid network, including:

[0069] The network controller is controlled using the P-θ and Qu control strategies to output the target control voltage.

[0070] The present invention is described below with specific cases:

[0071] like Figure 2 As shown in the figure, the wind turbine converter is connected to the grid through the L filter, and the virtual synchronous generator technology is used to realize the grid control to form a grid controller. The output duty cycle component of the grid controller is D abc .

[0072] The wind turbine converter adds a q-axis voltage controller, which outputs a duty cycle component ΔD. abc .

[0073] The duty cycle component ΔD output by the q-axis voltage controller abc The duty cycle component D output by the network controller abc Superposition, get the duty cycle d of the converter abc .

[0074] The q-axis voltage controller described above needs to use the q-axis voltage component U qp , U qn Calculate the negative sequence current using the following method:

[0075]

[0076] Among them, the calculation method of k1, k2, and k3 is:

[0077]

[0078] Among them, Z1, Z2, Z3, Z4, Z5, and Z6 are the action coefficients of positive and negative sequence voltages under asymmetric faults respectively; φ1 is the initial phase angle of Z1, φ2 is the initial phase angle of Z2, φ3 is the initial phase angle of Z3, φ4 is the initial phase angle of Z4, φ5 is the initial phase angle of Z5, and φ6 is the initial phase angle of Z6; U g is the grid-side voltage. In the dq axis coordinate system, U g =v d .

[0079] In the case of a single-phase grounding fault, the calculation formulas for Z1, Z2, Z3, Z4, Z5, and Z6 are as follows:

[0080]

[0081]

[0082] Among them, Z g1p , Z g2p , Z g1n , Z g2n They are positive and negative impedance 1, positive sequence impedance 2, negative sequence impedance 1, and negative sequence impedance 2 in the sequence equivalent circuit respectively.

[0083] The negative sequence current calculated by the q-axis voltage component of the q-axis voltage controller needs to not exceed the negative sequence current threshold Ω1, which is expressed as:

[0084] I n ≤Ω1

[0085] The q-axis voltage controller can calculate the q-axis voltage positive and negative sequence components that need to be injected as v according to the negative sequence current threshold Ω1. qrefp and v qrefn .

[0086] Among them, the grid controller is used to connect the wind turbine converter to the grid through the L filter, and adopts P-θ and Qu control to achieve synchronization and build the output voltage.

[0087] The q-axis voltage controller is used to improve the transient stability capability of the wind turbine converter under fault conditions.

[0088] like Figure 3 As shown, Figure 3Based on the double second-order generalized integrator positive and negative sequence separation method (DSOGI), DSOGI produces a 90° phase shift on the input sinusoidal signal to obtain two orthogonal signals. The positive and negative sequence calculation module obtains the positive and negative sequence components in the αβ coordinate system, and finally obtains the phase angle of the network controller and the q-axis voltage controller.

[0089] The present invention is based on the influence of positive and negative sequence voltages on transient stability of wind turbine converters during asymmetric faults. By introducing a q-axis voltage control link and coordinating with a hybrid synchronous control structure of network voltage control, the transient stability performance of wind turbine converters during asymmetric faults is improved.

[0090] The method of the present invention can be applied to the design of a wind turbine controller to improve the transient stability of a wind turbine converter during an asymmetric fault.

[0091] Embodiment 2:

[0092] The present invention also proposes a system 200 for hybrid networking synchronization control, such as Figure 4 As shown, including:

[0093] The first calculation unit 201 is used to determine the output duty cycle component D of the networking controller in the hybrid networking abc , and determine the output duty cycle component ΔD of the q-axis voltage controller in the hybrid network abc ;

[0094] The second calculation unit 202 is used to calculate the D abc and ΔD abc Perform superposition processing to obtain the duty cycle d of the wind turbine converter in the hybrid network abc ;

[0095] The third calculation unit 203 is used to calculate the abc , calculate the positive and negative sequence components of the voltage to be injected into the q-axis voltage controller;

[0096] A synchronization control unit 204, configured to perform synchronization control on the hybrid network according to the positive and negative sequence components of the voltage;

[0097] The wind turbine converter is connected to the power grid through an L filter to form a grid controller, and a q-axis voltage controller is added to the wind turbine converter to form a hybrid grid.

[0098] Among them, based on the d abc , the voltage positive and negative sequence components to be injected into the q-axis voltage controller are calculated, including:

[0099] Based on the d abc , determining a q-axis voltage component, and calculating a negative sequence current based on the q-axis voltage component;

[0100] Determining voltage positive and negative sequence components to be injected into a q-axis voltage controller based on the negative sequence current and a negative sequence current threshold of the negative sequence current;

[0101] The negative sequence current does not exceed a negative sequence current threshold.

[0102] Wherein, based on the q-axis voltage component, the calculation formula for the negative sequence current is calculated as follows:

[0103]

[0104] Among them, U qp and U qn is the q-axis voltage component, I n is the negative sequence current, U g is the grid-side voltage, k1, k2 and k3 are voltage action coefficients respectively.

[0105] The hybrid grid is synchronously controlled by using virtual synchronous generator technology and the positive and negative sequence components of the voltage, including:

[0106] The virtual synchronous generator technology is used to control the grid controller in the hybrid grid, and the q-axis voltage controller is synchronously controlled by the voltage positive and negative sequence components.

[0107] The virtual synchronous generator technology is used to control the network controller in the hybrid network, including:

[0108] The network controller is controlled using the P-θ and Qu control strategies to output the target control voltage.

[0109] The present invention improves the transient stability of the power grid by performing synchronous control on the hybrid grid.

[0110] Embodiment 3:

[0111] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the method in the above embodiment.

[0112] Embodiment 4:

[0113] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both a built-in storage medium in a computer device and an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiment.

[0114] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0115] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0116] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0117] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0118] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0119] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for hybrid networking synchronization control, characterized in that: include: Determine the output duty cycle component D of the networking controller in the hybrid networking abc , and determine the output duty cycle component ΔD of the q-axis voltage controller in the hybrid network abc ; For the D abc and ΔD abc Perform superposition processing to obtain the duty cycle d of the wind turbine converter in the hybrid network abc ; Based on the d abc , calculate the positive and negative sequence components of the voltage to be injected into the q-axis voltage controller; Synchronously controlling the hybrid network according to the positive and negative sequence components of the voltage; The wind turbine converter is connected to the power grid through an L filter to form a grid controller, and a q-axis voltage controller is added to the wind turbine converter to form a hybrid grid.

2. The method according to claim 1, characterized in that Based on the d abc , the voltage positive and negative sequence components to be injected into the q-axis voltage controller are calculated, including: Based on the d abc , determining a q-axis voltage component, and calculating a negative sequence current based on the q-axis voltage component; Determining voltage positive and negative sequence components to be injected into a q-axis voltage controller based on the negative sequence current and a negative sequence current threshold of the negative sequence current; The negative sequence current does not exceed a negative sequence current threshold.

3. The method according to claim 2, characterized in that The calculation formula for the negative sequence current calculated based on the q-axis voltage component is as follows: Among them, U qp and U qn is the q-axis voltage component, I n is the negative sequence current, U g is the grid-side voltage, k1, k2 and k3 are voltage action coefficients respectively.

4. The method according to claim 1, characterized in that: The method of synchronously controlling the hybrid grid by using the virtual synchronous generator technology and the positive and negative sequence components of the voltage includes: The virtual synchronous generator technology is used to control the grid controller in the hybrid grid, and the q-axis voltage controller is synchronously controlled by the voltage positive and negative sequence components.

5. The method according to claim 4, characterized in that The controlling of the network controller in the hybrid network by using the virtual synchronous generator technology includes: The grid controller is controlled by the active power-angle P-θ and reactive power-voltage Qu control strategies to output the target control voltage.

6. A system for hybrid networking synchronization control, characterized in that: include: The first calculation unit is used to determine the output duty cycle component D of the networking controller in the hybrid networking abc , and determine the output duty cycle component ΔD of the q-axis voltage controller in the hybrid network abc ; The second calculation unit is used to calculate the D abc and ΔD abc Perform superposition processing to obtain the duty cycle d of the wind turbine converter in the hybrid network abc ; The third calculating unit is used for abc , calculate the positive and negative sequence components of the voltage to be injected into the q-axis voltage controller; A synchronization control unit, used for performing synchronization control on the hybrid network according to the positive and negative sequence components of the voltage; The wind turbine converter is connected to the power grid through an L filter to form a grid controller, and a q-axis voltage controller is added to the wind turbine converter to form a hybrid grid.

7. The system according to claim 6, characterized in that Based on the d abc , the voltage positive and negative sequence components to be injected into the q-axis voltage controller are calculated, including: Based on the d abc , determining a q-axis voltage component, and calculating a negative sequence current based on the q-axis voltage component; Determining voltage positive and negative sequence components to be injected into a q-axis voltage controller based on the negative sequence current and a negative sequence current threshold of the negative sequence current; The negative sequence current does not exceed a negative sequence current threshold.

8. The system according to claim 7, characterized in that The calculation formula for the negative sequence current calculated based on the q-axis voltage component is as follows: Among them, U qp and U qn is the q-axis voltage component, I n is the negative sequence current, U g is the grid-side voltage, k1, k2 and k3 are voltage action coefficients respectively.

9. The system according to claim 6, characterized in that The method of synchronously controlling the hybrid grid by using the virtual synchronous generator technology and the positive and negative sequence components of the voltage includes: The virtual synchronous generator technology is used to control the grid controller in the hybrid grid, and the q-axis voltage controller is synchronously controlled by the voltage positive and negative sequence components.

10. The system according to claim 9, characterized in that The controlling of the network controller in the hybrid network by using the virtual synchronous generator technology includes: The network controller is controlled by P-θ and control strategy to output the target control voltage.

11. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 5 is implemented.

12. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 5 is implemented.

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