A method for suppressing oscillation of a multi-type network equipment interconnection system and application thereof

Abstract

The application discloses a kind of multi-type network equipment interconnection system oscillation suppression method and application, applied to distributed power supply grid-connected control technical field, method includes obtaining the network type converter network power angle dynamic data and output power;Based on the power synchronization coefficient obtained, the network power angle dynamic data and the output power are processed using high-pass filter, to obtain grid point power angle disturbance information, wherein the power synchronization coefficient is determined by the line impedance of network equipment interconnection system;Grid point power angle disturbance information is input into the gain processing in the power angle transfer nominal model constructed by power synchronization coefficient, to obtain net side power disturbance component;Using lead-lag filter, net side power disturbance component is power feedback processing, to generate additional damping torque, based on additional damping torque, network equipment interconnection system is oscillation suppressed.The method provided in the embodiment of the application can solve the interaction oscillation problem of multi-type network equipment interconnection system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of distributed power grid-connected control technology, in particular to an oscillation suppression method of a multi-type network-constructing equipment interconnection system and application. BACKGROUND

[0002] With the rapid development of renewable energy in the power grid, a large number of renewable energy is connected to the power grid through power electronic equipment, which makes the proportion of traditional synchronous generators based on mechanical torque relatively decrease, resulting in the decrease of system inertia year by year. In order to solve the problem of system inertia loss and further improve the penetration rate of renewable energy, network-constructing control is mainly used to provide inertia and frequency support for the power grid.

[0003] In the prior art, network-constructing control mainly includes droop control, virtual synchronous machine control and matching control, which all provide inertia support to the system by establishing a frequency generation mechanism similar to synchronous generators. However, the low-frequency oscillation mode of synchronous generators is also introduced into the system, which will cause the system oscillation to diverge.

[0004] In recent years, the suppression strategies proposed for the low-frequency oscillation problem of network-constructing control have been relatively mature in solving the oscillation suppression problem of single-type equipment. However, when different types of network-constructing equipment are connected in parallel, due to the mutual coupling of power-frequency dynamics, the low-frequency oscillation modes of different types of network-constructing converters will interact with each other, resulting in the failure of the low-frequency oscillation suppression strategies based on single-type network-constructing equipment.

[0005] Therefore, how to solve the interaction oscillation problem of the multi-type network-constructing equipment interconnection system has become a technical problem to be solved by those skilled in the art. SUMMARY

[0006] The present application provides an oscillation suppression method of a multi-type network-constructing equipment interconnection system and application, to solve the interaction oscillation problem of the multi-type network-constructing equipment interconnection system, to effectively suppress the low-frequency power oscillation caused by disturbance, prevent system instability, and ensure the stability of the system.

[0007] In order to solve the above technical problems, the present application provides an oscillation suppression method of a multi-type network-constructing equipment interconnection system, applied to a network-constructing equipment interconnection system including several types of network-constructing converters, the method comprising:

[0008] obtaining network-constructing power angle dynamic data and output power of the network-constructing converter;

[0009] based on the obtained power synchronization coefficient, processing the network-constructing power angle dynamic data and the output power by using a high-pass filter to obtain grid-connected point power angle disturbance information, wherein the power synchronization coefficient is determined by the line impedance of the network-constructing equipment interconnection system.

[0010] inputting the grid-connected point power angle disturbance information into a power angle transfer nominal model constructed by the power synchronization coefficient for gain processing to obtain a grid-side power disturbance component;

[0011] performing power feedback processing on the grid-side power disturbance component by using a lead-lag filter to generate an additional damping torque, wherein the power feedback processing process is configured to perform torque conversion processing on the grid-side power disturbance component, perform phase compensation processing on the obtained additional damping torque reference value by using a lead-lag filter to obtain the additional damping torque;

[0012] performing oscillation suppression on the grid-connected device interconnection system based on the additional damping torque.

[0013] As one of the preferred solutions, the determination process of the power synchronization coefficient includes:

[0014] obtaining a rated voltage of the grid-connected converter, a rated voltage of the grid-connected device interconnection system, and a line impedance of the grid-connected device interconnection system;

[0015] inputting the rated voltage of the grid-connected converter, the rated voltage of the grid-connected device interconnection system, and the line impedance of the grid-connected device interconnection system into a coefficient relationship formula to obtain the power synchronization coefficient.

[0016] As one of the preferred solutions, based on the obtained power synchronization coefficient, the grid-connected power angle dynamic data and the output power are processed by using a high-pass filter to obtain grid-connected point power angle disturbance information, including:

[0017] processing the grid-connected power angle dynamic data and the power synchronization coefficient to obtain a system-side power reference value;

[0018] based on the system-side power reference value and the output power, obtaining initial power angle disturbance information;

[0019] processing the initial power angle disturbance information by using a high-pass filter to obtain the grid-connected point power angle disturbance information.

[0020] As one of the preferred solutions, the grid-connected point power angle disturbance information is inputted into a power angle transfer nominal model constructed by the power synchronization coefficient for gain processing to obtain a grid-side power disturbance component, including:

[0021] processing the power synchronization coefficient based on a linearization modeling technology to obtain a power angle transfer nominal model;

[0022] The grid-connected point power angle disturbance information is input into the power angle transfer nominal model for gain processing to obtain the grid-side power disturbance component.

[0023] As one of the preferred solutions, the grid-side power disturbance component is subjected to power feedback processing by using a lead-lag filter to generate an additional damping torque, which includes:

[0024] The grid-side power disturbance component is subjected to normalization processing based on real-time speed dynamic conversion to obtain a normalized power disturbance signal;

[0025] The normalized power disturbance signal is subjected to torque conversion processing to obtain an additional damping torque reference value;

[0026] The additional damping torque reference value is subjected to phase compensation processing by using a lead-lag filter to obtain the additional damping torque.

[0027] As one of the preferred solutions, the grid-connected device interconnection system is subjected to oscillation suppression based on the additional damping torque, which includes:

[0028] The additional damping torque is subjected to reference value limiting processing to obtain an oscillation suppression power reference instruction;

[0029] Based on the oscillation suppression power reference instruction, the grid-connected device interconnection system is subjected to oscillation suppression by the internal control loop of the grid-connected converter.

[0030] As one of the preferred solutions, after the grid-connected device interconnection system is subjected to oscillation suppression based on the additional damping torque, the oscillation suppression method of the multi-type grid-connected device interconnection system further includes:

[0031] The first power oscillation amplitude of the multi-type grid-connected device interconnection system before oscillation suppression is obtained; the second power oscillation amplitude of the multi-type grid-connected device interconnection system after oscillation suppression is obtained;

[0032] The first power oscillation amplitude and the second power oscillation amplitude are evaluated and analyzed by using Fourier analysis to obtain a residual oscillation amplitude value;

[0033] Based on the residual oscillation amplitude value, the oscillation suppression method is optimized.

[0034] The present application further provides an oscillation suppression device for a multi-type grid-connected device interconnection system, which is applied to a grid-connected device interconnection system including a plurality of types of grid-connected converters, and includes:

[0035] An acquisition module is configured to acquire grid-connected power angle dynamic data and output power of the grid-connected converter.

[0036] a processing module, configured to process the grid-forming power angle dynamic data and the output power by using a high-pass filter based on an obtained power synchronization coefficient, to obtain grid-connected point power angle disturbance information, wherein the power synchronization coefficient is determined by line impedance of the grid-forming device interconnection system;

[0037] a gain module, configured to input the grid-connected point power angle disturbance information into a power angle transfer nominal model constructed by the power synchronization coefficient for gain processing, to obtain a grid-side power disturbance component;

[0038] a generation module, configured to perform power feedback processing on the grid-side power disturbance component by using a lead-lag filter to generate an additional damping torque, wherein the power feedback processing process is configured to perform torque conversion processing on the grid-side power disturbance component, and perform phase compensation processing on an obtained additional damping torque reference value by using the lead-lag filter to obtain the additional damping torque;

[0039] a suppression module, configured to perform oscillation suppression on the grid-forming device interconnection system based on the additional damping torque.

[0040] The application further provides a grid-forming device interconnection system oscillation suppression device of multiple types, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the grid-forming device interconnection system oscillation suppression method as described above when executing the computer program.

[0041] The application further provides a computer readable storage medium, which stores a computer program, and when a device where the computer readable storage medium is located executes the computer program, the grid-forming device interconnection system oscillation suppression method as described above is implemented.

[0042] Compared with the prior art, the beneficial effects of the embodiments of the application are at least one of the following:

[0043] The application obtains network-forming power angle dynamic data and output power of the network-forming converter, processes the network-forming power angle dynamic data and the output power by using a high-pass filter based on the obtained power synchronization coefficient to obtain grid-connected point power angle disturbance information, wherein the power synchronization coefficient is determined by line impedance of the network-forming device interconnection system, inputs the grid-connected point power angle disturbance information into a power angle transfer nominal model constructed by the power synchronization coefficient for gain processing to obtain a grid-side power disturbance component, processes the grid-side power disturbance component by using a lead-lag filter for power feedback processing to generate additional damping torque, wherein the power feedback processing process is configured to perform torque conversion processing on the grid-side power disturbance component, performs phase compensation processing on the obtained additional damping torque reference value by using a lead-lag filter to obtain the additional damping torque, and suppresses oscillation of the network-forming device interconnection system based on the additional damping torque.

[0044] Compared with the prior art, the application solves the problem of invalidation of oscillation suppression strategies of different types of network-forming devices in parallel operation by multi-dimensional data monitoring, differential modeling and adaptive damping control. Specifically, the scheme first obtains network-forming power angle dynamic data and power of the network-forming converter to form local monitoring, and processes the grid-connected point power angle disturbance information by combining the power synchronization coefficient which is calculated in real time and can differentially represent the power-frequency coupling characteristics of different devices. Then, the information is input into a power angle transfer nominal model constructed by the power synchronization coefficient to accurately locate the oscillation source and propagation path to obtain the grid-side power disturbance component. Finally, the lead-lag filter which can be optimized in the frequency domain for multi-modal coupling is used to generate additional damping torque by power feedback processing of the grid-side power disturbance component, and modal decoupling and energy balance are realized by inputting differential damping torque to different types of devices, thereby effectively suppressing the oscillation of the network-forming device interconnection system, breaking through the limitations of traditional single device strategies, and adapting to complex working conditions of heterogeneous network-forming devices in parallel. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is a flowchart of the oscillation suppression method of the multi-type network-forming device interconnection system in one embodiment of the application;

[0046] Figure 2 is a structural schematic diagram of the oscillation suppression device of the multi-type network-forming device interconnection system in one embodiment of the application;

[0047] Figure 3 is a structural schematic diagram of the oscillation suppression device of the multi-type network-forming device interconnection system in one embodiment of the application;

[0048] REFERENCE SIGNS:

[0049] Wherein, 11, acquisition module; 12, processing module; 13, gain module; 14, generation module; 15, suppression module; 21, processor; 22, memory. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. The purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0051] In the description of the present application, the terms "first", "second", "third" and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", "third" and the like can be explicitly or implicitly included one or more features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0052] In the description of the present application, it should be noted that, unless otherwise defined, all technical and scientific terms used in the present application are the same as the meanings understood by those skilled in the art. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] An embodiment of the present application provides an oscillation suppression method of a multi-type network equipment interconnection system, specifically, please refer to Figure 1 , Figure 1 The flowchart of the oscillation suppression method of the multi-type network equipment interconnection system in one embodiment of the present application is shown, the method is applied to the network equipment interconnection system including several types of network type converters, including:

[0054] S1: obtaining the network angle dynamic data and output power of the network type converter;

[0055] S2: based on the obtained power synchronization coefficient, the network angle dynamic data and output power are processed by using a high-pass filter to obtain the grid point angle disturbance information, wherein the power synchronization coefficient is determined by the line impedance of the network equipment interconnection system;

[0056] S3: inputting the grid point angle disturbance information into the angle transfer nominal model constructed by the power synchronization coefficient for gain processing to obtain the grid side power disturbance component;

[0057] S4: performing power feedback processing on the grid-side power disturbance component by using a lead-lag filter to generate an additional damping torque, wherein the power feedback processing process is configured to perform torque conversion processing on the grid-side power disturbance component, and perform phase compensation processing on the obtained additional damping torque reference value by using the lead-lag filter to obtain the additional damping torque.

[0058] S5: performing oscillation suppression on the grid equipment interconnection system based on the additional damping torque.

[0059] Specifically, power angle dynamic data of several types of grid-type converters in the grid equipment interconnection system, i.e., grid power angle dynamic data, are obtained, and output power of the grid-type converters is obtained, wherein the power output by the grid-type converters themselves needs to be measured, and the power angle dynamic data of the grid-type converters themselves can be directly obtained in the control system.

[0060] Specifically, the grid power angle dynamic data generally refers to power angle fluctuation characteristic parameters, such as fluctuation amplitude and fluctuation frequency, etc.; and the grid power angle dynamic data is essentially the phase difference of the voltages on both sides of the connection node.

[0061] In step S2, based on the obtained power synchronization coefficient, the grid power angle dynamic data and the output power are processed by using a high-pass filter to obtain grid point power angle disturbance information, wherein the power synchronization coefficient is determined by the line impedance of the grid equipment interconnection system.

[0062] Specifically, the determination process of the power synchronization coefficient includes: obtaining the rated voltage of the grid-type converter, the rated voltage of the grid equipment interconnection system, and the line impedance of the grid equipment interconnection system; inputting the rated voltage of the grid-type converter, the rated voltage of the grid equipment interconnection system, and the line impedance of the grid equipment interconnection system into a coefficient relationship formula to obtain the power synchronization coefficient.

[0063] Based on the power synchronization coefficient, the grid power angle dynamic data and the output power are processed by using a high-pass filter to obtain power angle disturbance information, specifically including: processing the grid power angle dynamic data and the power synchronization coefficient to obtain a system-side power reference value; based on the system-side power reference value and the output power, obtaining initial power angle disturbance information; processing the initial power angle disturbance information by using a high-pass filter to obtain the power angle disturbance information.

[0064] Specifically, the grid power angle dynamic data is the difference between the voltage phase of the grid point and the voltage phase of the equivalent infinite grid; the power synchronization coefficient is a key parameter for quantifying the system synchronization characteristic, and its value is determined by the circuit topology, including the output voltage, the line impedance, and the grid point voltage, and its essence is to establish a quantitative correlation between the power angle change and the power regulation.

[0065] Firstly, the power synchronization coefficient is determined by system parameter identification or preset configuration; then the real-time power angle value in the grid-connected power angle dynamic data is extracted, and the power angle value is quantitatively operated with the power synchronization coefficient, and finally the system-side power reference value is obtained. The quantitative operation is usually multiplication, because the synchronization coefficient is essentially a conversion factor from power angle to power.

[0066] The grid-connected power angle itself is a phase difference signal and cannot be directly compared with the output power of the converter. After the power synchronization coefficient is converted into the system-side power reference value, a unified comparison dimension of the actual output power of the converter and the system expected power is established, which provides a reference for subsequent judgment of whether there is disturbance.

[0067] The power deviation value obtained by difference operation between the actual output power of the converter and the system-side power reference value is the initial power angle disturbance information. The logic is that when the system has no disturbance, the converter and the grid are in synchronization, and the grid-connected power angle remains at the ideal value. At this time, the actual output power should be consistent with the system-side power reference value, and the deviation is 0. When the system has disturbance, such as load mutation and grid voltage fluctuation, the grid-connected power angle deviates from the ideal value, resulting in deviation between the actual output power and the reference value. The deviation directly reflects the influence of power angle disturbance on power output, and is therefore defined as the initial power angle disturbance information.

[0068] By comparing the actual power with the reference power, the abstract power angle disturbance is converted into a quantifiable power deviation, completing the mapping from synchronization state anomaly to power signal deviation and laying a foundation for subsequent accurate extraction of disturbance information. However, the initial information extraction at this time is the real-time dynamic of the grid-connected point power angle, which contains both steady-state components and disturbance components, mainly the direct current component of steady-state operation.

[0069] The initial power angle disturbance information is processed by a low-bandwidth high-pass filter to purify the disturbance signal and filter out the direct current static deviation, and finally a signal containing only low frequency is output, i.e. the final power angle disturbance information.

[0070] The power angle disturbance information is input into the power angle transfer nominal model constructed by the power synchronization coefficient for gain processing to obtain the grid-side power disturbance component, including: based on linearization modeling technology, the power synchronization coefficient is processed to obtain the power angle transfer nominal model; the power angle disturbance information is input into the power angle transfer nominal model for gain processing to obtain the grid-side power disturbance component.

[0071] Specifically, before modeling, it is necessary to clarify that the synchronization system composed of the grid-connected converter and the grid is essentially a nonlinear system, and the power angle transfer is concerned about the dynamic transfer relationship from power angle disturbance to power response. Direct analysis of nonlinear systems will lead to complex mathematical models and difficulty in solving, so linearization modeling technology is needed to simplify the system characteristics.

[0072] Therefore, based on the linearization modeling technology, the correlation between the nonlinear link and the power synchronization coefficient at the typical steady-state operating point of the grid-forming system is extracted, the Taylor expansion and other linearization methods are used to substitute the power synchronization coefficient into the linear equation, the linear transfer relationship between the power angle input and the power output is determined, and finally the power angle transfer nominal model is formed. It should be noted that the nominal here refers to the model based on ideal parameters, which is a benchmark model for describing the power angle-power transfer.

[0073] The power angle disturbance information is connected to the input end of the power angle transfer nominal model, and the model processes the input signal according to its own linear transfer relationship. Specifically, the gain is determined by the power synchronization coefficient and the linearized system parameters. The larger the power synchronization coefficient, the higher the model gain, and the stronger the power disturbance output amplitude corresponding to the same power angle disturbance.

[0074] The signal output by the model after gain processing is the grid-side power disturbance component.

[0075] The grid-side power disturbance component is processed by a lead-lag filter for power feedback, generating an additional damping torque, including: based on the real-time speed, the grid-side power disturbance component is normalized to obtain a normalized power disturbance signal; the normalized power disturbance signal is converted into torque to obtain an additional damping torque reference value; the additional damping torque reference value is phase compensated by a lead-lag filter to obtain an additional damping torque.

[0076] That is, the power feedback processing process is configured to convert the grid-side power disturbance component into torque, and the obtained additional damping torque reference value is phase compensated by a lead-lag filter to obtain an additional damping torque.

[0077] Normalization is a common dimensionless processing method in power systems and converter control, the core of which is to convert physical quantities (here, the grid-side power disturbance component) into proportional coefficients relative to a certain reference value, eliminating unit differences and numerical magnitude effects, and ensuring the universality and accuracy of subsequent control logic.

[0078] In this process, the real-time speed of the grid-forming converter or its associated rotating parts is first obtained, which is usually the electrical angular velocity. This speed reflects the current dynamic operating state of the system and is the basis for dynamic adjustment of the reference value; according to the real-time speed and the rated parameters of the system, the power reference value under the current working condition is dynamically generated according to the calculation formula of the power reference; the grid-side power disturbance component obtained previously is divided by the power reference value dynamically generated at the current time to obtain the dimensionless normalized power disturbance signal.

[0079] According to the basic principle of electromechanical energy conversion, the conversion formula after normalization is derived. In the normalized system, the relationship is simplified as "normalized torque = normalized power / normalized angular velocity". The normalized power disturbance signal obtained in the first step is substituted into the conversion formula with the current working condition of the normalized real-time speed. The additional damping torque reference value is obtained through division operation. Then the phase lag degree of the additional damping torque reference value is judged through signal detection, and the phase range that needs to be compensated by the filter is determined. According to the phase range that needs to be compensated, the lead and lag link parameters of the filter are set. The additional damping torque reference value is input into the configured lead-lag filter. The filter advances the phase of the reference value through the lead link, smooths the signal and suppresses the noise through the lag link, and finally outputs the additional damping torque with synchronized phase and stable amplitude.

[0080] It should be noted that the lead-lag link is performed simultaneously, which has the function of modifying the gain and phase.

[0081] Based on the additional damping torque, the oscillation suppression of the interconnected system of grid-forming equipment is carried out, including: the reference value limiting processing of the additional damping torque is carried out to obtain the oscillation suppression power reference instruction; based on the oscillation suppression power reference instruction, the oscillation suppression of the interconnected system of grid-forming equipment is carried out through the internal control loop of the grid-forming converter.

[0082] Before this step, the safe operation boundary of the interconnected system of grid-forming equipment needs to be determined. The boundary is determined by the rated power of the grid-forming converter, the withstand capability of the switching device, the system bus voltage stability threshold and other hardware parameters and operation constraints. According to this, the reasonable value range of the additional damping torque is set.

[0083] Then the additional damping torque generated in the early stage is compared with the value range in real time. If the additional damping torque is within the set range, it is directly converted into the corresponding oscillation suppression power reference instruction. If the additional damping torque exceeds the upper limit value, the upper limit value is taken as the reference to convert into the oscillation suppression power reference instruction. If it is lower than the lower limit value, the lower limit value is taken as the reference to convert into the oscillation suppression power reference instruction, so as to ensure that the finally output oscillation suppression power reference instruction is always within the system safe operation interval.

[0084] After receiving the vibration suppression power reference instruction, the power control loop of the grid-connected converter compares it with the actual output power of the converter, calculates a power deviation signal, which is input into a proportional-integral (PI) controller, and generates a corresponding current reference instruction after operation processing, which needs to meet the system regulation requirements for active power and reactive power and match the vibration suppression target.

[0085] After the oscillation suppression of the multi-type grid-connected equipment interconnected system based on the additional damping torque, the oscillation suppression method of the multi-type grid-connected equipment interconnected system further includes: obtaining a first power oscillation amplitude of the multi-type grid-connected equipment interconnected system before oscillation suppression; obtaining a second power oscillation amplitude of the multi-type grid-connected equipment interconnected system after oscillation suppression; performing evaluation analysis on the first power oscillation amplitude and the second power oscillation amplitude by using Fourier analysis to obtain a residual oscillation amplitude; and optimizing the oscillation suppression method based on the residual oscillation amplitude.

[0086] Another embodiment of the present application provides an oscillation suppression device of a multi-type grid-connected equipment interconnected system, and specifically, please refer to Figure 2 , Figure 2 The flowchart shows the oscillation suppression device of the multi-type grid-connected equipment interconnected system in one embodiment of the present application, and the device includes:

[0087] The obtaining module 11 is configured to obtain grid-connected power angle dynamic data and output power of the grid-connected converter.

[0088] The processing module 12 is configured to process the grid-connected power angle dynamic data and the output power by using a high-pass filter based on the obtained power synchronization coefficient to obtain grid-connected point power angle disturbance information, wherein the power synchronization coefficient is determined by line impedance of the grid-connected equipment interconnected system.

[0089] The gain module 13 is configured to input the grid-connected point power angle disturbance information into a power angle transfer nominal model constructed by the power synchronization coefficient for gain processing to obtain a grid-side power disturbance component.

[0090] The generating module 14 is configured to generate an additional damping torque by performing power feedback processing on the grid-side power disturbance component using a lead-lag filter, wherein the power feedback processing process is configured to perform torque conversion processing on the grid-side power disturbance component, and perform phase compensation processing on the obtained additional damping torque reference value using the lead-lag filter to obtain the additional damping torque.

[0091] The damping module 15 is configured to perform oscillation damping on the multi-type grid-connected device interconnection system based on the additional damping torque.

[0092] Referring to Figure 3 which is a structural schematic diagram of the oscillation damping device for the multi-type grid-connected device interconnection system provided in the embodiments of the present application. The oscillation damping device for the multi-type grid-connected device interconnection system provided in the embodiments of the present application comprises a processor 21, a memory 22, and a computer program stored in the memory 22 and configured to be executed by the processor 21. When the processor 21 executes the computer program, the steps in the oscillation damping method embodiments for the multi-type grid-connected device interconnection system described above are implemented, such as steps S1-S5 in the embodiment of the oscillation damping method for the multi-type grid-connected device interconnection system. Alternatively, when the processor 21 executes the computer program, the functions of the modules in the above-described various device embodiments are implemented, such as the functions of the obtaining module 11. Figure 1

[0093] For example, the computer program can be divided into one or more modules, which are stored in the memory 22 and executed by the processor 21 to complete the present application. One or more modules can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the oscillation damping device for the multi-type grid-connected device interconnection system. For example, the computer program can be divided into the obtaining module 11, the processing module 12, the gain module 13, etc., and the specific functions of the modules are as follows:

[0094] The obtaining module 11 is configured to obtain grid-connected power angle dynamic data and output power of a grid-connected converter.

[0095] The processing module 12 is configured to obtain grid-connected point power angle disturbance information by performing processing on the grid-connected power angle dynamic data and the output power using a high-pass filter based on the obtained power synchronization coefficient, wherein the power synchronization coefficient is determined by the line impedance of the grid-connected device interconnection system.

[0096] The gain module 13 is configured to input the grid-connected point power angle disturbance information into a power angle transfer nominal model constructed by the power synchronization coefficient to perform gain processing, and obtain the grid-side power disturbance component.

[0097] ​The generating module 14 is configured to generate the additional damping torque by performing power feedback processing on the grid-side power disturbance component using a lead-lag filter, wherein the power feedback processing process is configured to perform torque conversion processing on the grid-side power disturbance component, and perform phase compensation processing on the obtained additional damping torque reference value using the lead-lag filter to obtain the additional damping torque.

[0098] The suppressing module 15 is configured to perform oscillation suppression on the multi-type grid equipment interconnected system based on the additional damping torque.

[0099] The multi-type grid equipment interconnected system oscillation suppression device can include, but is not limited to, a processor 21 and a memory 22. Those skilled in the art can understand that the schematic diagram is only an example of the multi-type grid equipment interconnected system oscillation suppression device, and does not constitute a limitation on the multi-type grid equipment interconnected system oscillation suppression device, and can include more or fewer components than the schematic diagram, or combine certain components, or different components, for example, the multi-type grid equipment interconnected system oscillation suppression device can also include an input / output device, a network access device, a bus, etc.

[0100] The processor 21 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor or the like. The processor 21 is the control center of the multi-type grid equipment interconnected system oscillation suppression device, and connects various parts of the entire multi-type grid equipment interconnected system oscillation suppression device through various interfaces and lines.

[0101] The memory 22 can be used to store computer programs and / or modules, and the processor 21 realizes various functions of the oscillation suppression device of the multi-type networking device interconnection system by running or executing the computer programs and / or modules stored in the memory 22 and calling the data stored in the memory 22. The memory 22 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application program required for a function (such as a sound playing function, an image playing function, etc.), and the like; and the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), and the like. In addition, the memory 22 can include a high-speed random access memory, and can also include a non-volatile memory, for example, a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0102] The modules integrated in the oscillation suppression device of the multi-type networking device interconnection system can be stored in a computer readable storage medium if they are realized in the form of software function units and sold or used as independent products. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. The computer program can implement the steps of the above-mentioned various method embodiments when executed by a processor. The computer program includes computer program code, which can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0103] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware, and the program can be stored in a computer readable storage medium, and the program can include the processes of the above-mentioned various method embodiments when executed. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0104] Correspondingly, the embodiment of the present application provides a computer readable storage medium, which comprises a stored computer program, wherein when the computer program runs, the computer readable storage medium controls the device where the computer readable storage medium is located to execute the steps in the oscillation suppression method of the multi-type network equipment interconnection system of the above-mentioned embodiment, for example Figure 1 steps S1-S5 in the method.

[0105] The above-mentioned embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as a limitation on the patent scope of the present application. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A method for oscillation suppression in a multi-type network interconnection system, characterized in that, Applied to interconnection systems of grid-connected equipment including several types of grid-connected converters, including: Obtain the dynamic data of the grid-type converter's power angle and output power; Based on the obtained power synchronization coefficient, the grid-connected power angle dynamic data and the output power are processed using a high-pass filter to obtain grid-connected point power angle disturbance information. This includes: processing the grid-connected power angle dynamic data and the power synchronization coefficient to obtain a system-side power reference value; obtaining initial power angle disturbance information based on the system-side power reference value and the output power; and processing the initial power angle disturbance information using a high-pass filter to obtain grid-connected point power angle disturbance information. The power synchronization coefficient is determined by the line impedance of the interconnection system of the grid-connected equipment. The power angle disturbance information at the grid connection point is input into the power angle transfer nominal model constructed by the power synchronization coefficient for gain processing to obtain the grid-side power disturbance component. The power feedback processing of the grid-side power disturbance component is performed using a lead-lag filter to generate an additional damping torque. The power feedback processing is configured to perform torque conversion processing on the grid-side power disturbance component, and the additional damping torque reference value is phase compensated using a lead-lag filter to obtain the additional damping torque. The oscillation of the interconnected network equipment system is suppressed based on the additional damping torque.

2. The oscillation suppression method for a multi-type network interconnection system as described in claim 1, characterized in that, The process of determining the power synchronization coefficient includes: Obtain the rated voltage of the grid-type converter, the rated voltage of the grid-connected equipment interconnection system, and the line impedance of the grid-connected equipment interconnection system; The rated voltage of the grid-type converter, the rated voltage of the grid-connected equipment interconnection system, and the line impedance of the grid-connected equipment interconnection system are input into the coefficient relationship to obtain the power synchronization coefficient.

3. The oscillation suppression method for a multi-type network interconnection system as described in claim 1, characterized in that, The step of inputting the power angle disturbance information at the grid connection point into the power angle transfer nominal model constructed from the power synchronization coefficient for gain processing to obtain the grid-side power disturbance component includes: Based on linear modeling technology, the power synchronization coefficient is processed to obtain the nominal power angle transfer model; The power angle disturbance information at the grid connection point is input into the power angle transfer nominal model for gain processing to obtain the grid-side power disturbance component.

4. The oscillation suppression method for a multi-type network interconnection system as described in claim 1, characterized in that, The step of using a lead-lag filter to perform power feedback processing on the grid-side power disturbance component to generate additional damping torque includes: The grid-side power disturbance component is normalized based on the dynamic conversion of real-time rotational speed to obtain a normalized power disturbance signal. The per-unit power disturbance signal is subjected to torque conversion processing to obtain an additional damping torque reference value; The additional damping torque is obtained by performing phase compensation processing on the reference value of the additional damping torque using a lead-lag filter.

5. The oscillation suppression method for a multi-type network interconnection system as described in claim 1, characterized in that, The oscillation suppression of the interconnected network equipment system based on the additional damping torque includes: The additional damping torque is subjected to reference value limiting processing to obtain the vibration suppression power reference command; Based on the vibration suppression power reference command, the internal control loop of the grid-type converter is used to suppress oscillations in the interconnected system of the grid-type equipment.

6. The oscillation suppression method for a multi-type network interconnection system as described in claim 1, characterized in that, After suppressing oscillations in the interconnected network equipment system based on the additional damping torque, the oscillation suppression method for the multi-type interconnected network equipment system further includes: Obtain the first power oscillation amplitude of the multi-type network device interconnection system before oscillation suppression; obtain the second power oscillation amplitude of the multi-type network device interconnection system after oscillation suppression; Fourier analysis was used to evaluate and analyze the amplitudes of the first and second power oscillations to obtain the remaining oscillation amplitude. Based on the remaining oscillation amplitude, the oscillation suppression method is optimized.

7. An oscillation suppression device for a multi-type network interconnection system, characterized in that, Applied to interconnection systems of grid-connected equipment including several types of grid-connected converters, including: The acquisition module is used to acquire the dynamic data of the grid-connected power angle and the output power of the grid-connected converter; The processing module is used to process the dynamic power angle data of the grid structure and the output power using a high-pass filter based on the obtained power synchronization coefficient to obtain the power angle disturbance information at the grid connection point. This includes: processing the dynamic power angle data of the grid structure and the power synchronization coefficient to obtain a system-side power reference value; obtaining initial power angle disturbance information based on the system-side power reference value and the output power; and processing the initial power angle disturbance information using a high-pass filter to obtain the power angle disturbance information at the grid connection point. The power synchronization coefficient is determined by the line impedance of the interconnection system of the grid-connected equipment. The gain module is used to input the power angle disturbance information at the grid connection point into the power angle transfer nominal model constructed by the power synchronization coefficient for gain processing to obtain the grid-side power disturbance component; The generation module is used to perform power feedback processing on the grid-side power disturbance component using a lead-lag filter to generate an additional damping torque. The power feedback processing is configured to perform torque conversion processing on the grid-side power disturbance component and perform phase compensation processing on the obtained additional damping torque reference value using a lead-lag filter to obtain the additional damping torque. An oscillation suppression module is used to suppress oscillations in the interconnected network of devices based on the additional damping torque.

8. An oscillation suppression device for a multi-type network interconnection system, characterized in that, The system includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the oscillation suppression method for a multi-type interconnected network device system as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein when the device containing the computer-readable storage medium executes the computer program, it implements the oscillation suppression method for a multi-type network interconnection system as described in any one of claims 1 to 6.

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