Wideband oscillation full-electromagnetic transient digital-analog true detection system based on hardware-in-loop

Abstract

The invention discloses a hardware-in-loop-based broadband oscillation full-electromagnetic transient digital-analog simulation detection system. An upper computer is provided with an alternating current power grid full-electromagnetic transient digital model which is built by digital-analog simulation software and is accessed by large-scale new energy; the parallel computer is used for realizing in-loop digital-analog hybrid real-time simulation of the digital model and the actual physical control protection device to obtain a simulation calculation result; the digital-analog simulation interface device is used for transmitting a simulation calculation result of the parallel computer to the broadband oscillation detection device according to an appointed channel according to analog quantity configuration of a concerned branch in a digital model and a signal table communicated with the digital-analog simulation interface device; an action command of the broadband oscillation detection device is received as an input quantity and is returned to the digital model through the parallel computer, and the digital model executes a preset control strategy according to the action command; and the broadband oscillation detection device is used for carrying out broadband oscillation detection on the digital model according to the simulation calculation result transmitted by the digital-analog simulation interface device.

Description

Technical Field

[0001] The present invention relates to the technical field of safe and stable operation of large AC power grids connected with large-scale new energy and new power electronic equipment, and more specifically, to a wide-band oscillation full electromagnetic transient digital simulation detection system based on hardware-in-the-loop. Background Art

[0002] In order to meet the needs of energy transformation and environmental protection, renewable clean energy and power electronic equipment account for an increasing proportion in the AC power grid. Subsynchronous and supersynchronous oscillation accidents occur frequently, seriously affecting the safe and stable operation of the power system. Different types of disturbance components, such as harmonics, interharmonics, and oscillation quantities, have different causes and corresponding suppression methods. In order to deal with the broadband oscillation phenomenon in the new power system,

[0003] Researchers at home and abroad have proposed many methods for detecting broadband oscillation signals, mainly including: discrete Fourier transform, Planny parameter estimation method, wavelet analysis method and Hilbert-Huang transform method, etc. Many broadband oscillation detection devices have been developed for the detection and identification technology of disturbance frequency.

[0004] In order to apply these technologies and devices to actual power grids, it is urgent to test the safety, accuracy, reliability, etc. of these wide-band oscillation detection devices based on different principles. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a broadband oscillation full electromagnetic transient digital simulation detection system based on hardware-in-the-loop.

[0006] According to one aspect of the present invention, a broadband oscillation full electromagnetic transient digital simulation detection system based on hardware in the loop is provided, comprising: a host computer, a parallel computer, a digital simulation interface device and a broadband oscillation detection device, wherein:

[0007] The host computer is equipped with a digital model of the full electromagnetic transient state of the AC power grid with large-scale new energy access built with digital simulation software;

[0008] Parallel computers are used to realize the real-time simulation of digital-analog hybrid of digital models and actual physical control and protection devices in the loop to obtain simulation calculation results;

[0009] The digital-analog simulation interface device is used to realize hardware-in-the-loop. According to the analog quantity configuration of the branch concerned in the digital model and the signal table of the communication of the digital-analog simulation interface device, the simulation calculation result of the parallel computer is transmitted to the wide-band oscillation detection device according to the specified channel, and the action command of the wide-band oscillation detection device is received as the input quantity and returned to the digital model through the parallel computer. The digital model executes the preset control strategy according to the action command;

[0010] The wideband oscillation detection device is used to perform wideband oscillation detection on the digital model according to the simulation calculation result transmitted by the digital-analog simulation interface device, and determine the action command of the digital model according to the detection result and return it to the digital-analog simulation interface device.

[0011] Optionally, the digital model is a full electromagnetic transient digital model of a large AC power grid or a recommended power grid model built according to actual needs.

[0012] Optionally, the electrical decoupling principle of the parallel computer is to perform electrical decoupling through a decoupling element, and select a primary side line of the transformer that exceeds a preset length for decoupling.

[0013] Optionally, the broadband oscillation detection of the broadband oscillation detection device includes: detecting the stable power flow of the digital model, and detecting the steady-state power flow of the digital model through the bus voltage of the key nodes and the current and power of the key branches.

[0014] Optionally, the broadband oscillation detection of the broadband oscillation detection device further includes: detecting the real-time performance of the operation of the digital model.

[0015] Optionally, the broadband oscillation detection of the broadband oscillation detection device also includes: monitoring whether the voltage, current, and power parameters of the branch are consistent with the voltage, current, and power parameters in the digital model; if the data are inconsistent, preferentially adjusting the analog quantity ratio received by the broadband device; if the adjustable range of the analog quantity ratio of the broadband device is less than a preset value, adding a ratio to the analog quantity sent in the digital model.

[0016] Optionally, the injection method of the fault characteristic frequency component of the digital model includes:

[0017] By adjusting the parameters of the new energy model connected to the monitoring branch in the digital model, the system oscillation is caused;

[0018] In the monitoring branch of the digital model, a controllable current source is incorporated, and different frequencies and amplitudes are set in the controllable current source to inject harmonic current into the system;

[0019] In the monitoring branch of the digital model, on the system side, a controllable voltage source and its control loop are connected in series, and the fault characteristic frequency and amplitude to be injected are set in the controllable voltage source. The control loop is used to control the enabling of the controllable voltage source.

[0020] Optionally, the monitoring function test of the broadband oscillation detection device includes:

[0021] Test the steady-state measurement function and fault characteristic frequency measurement function of the widescreen oscillation monitoring device;

[0022] Test whether the widescreen oscillation monitoring device correctly displays all potential fault characteristic frequency components;

[0023] Inject various fault characteristic frequency components into the monitoring branch of the digital model to check whether the widescreen oscillation monitoring device can normally monitor the disturbance fault frequency and amplitude.

[0024] Optionally, the control strategy test of the broadband oscillation detection device includes:

[0025] After the fault characteristic frequency component added to the monitoring branch of the digital model exceeds the action threshold set by the device, check whether the analog quantity display of each branch of the device is correct;

[0026] Put the general function pressure plate of the broadband oscillation detection device into operation to detect whether the broadband oscillation detection device operates correctly and whether the action message is correct, and cut off the faulty branch in the correct order according to the established control strategy; whether the export signal of the wide-screen oscillation monitoring device is sent to the digital model through the interface device; after the digital model receives the action signal sent by the device, it cuts off the faulty branch in the digital model.

[0027] Therefore, the present invention provides a broadband oscillation full electromagnetic transient digital simulation detection system based on hardware-in-the-loop, which performs full electromagnetic transient digital simulation on the AC power grid with large-scale new energy access, and has the characteristics of large simulation scale and high accuracy. Then, through the hardware-in-the-loop method, real-time simulation (simulation step size of 50 microseconds) is performed with the broadband oscillation detection device, and various broadband detection devices can be accurately and reliably tested, providing reliable support for the application of the device in the actual power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0029] Figure 1 It is a schematic structural diagram of a wide-band oscillation full electromagnetic transient digital simulation detection system based on hardware-in-the-loop provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0030] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described here.

[0031] It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0032] Those skilled in the art can understand that the terms "first" and "second" in the embodiments of the present invention are only used to distinguish different steps, devices or modules, etc., and neither represent any specific technical meaning nor indicate the necessary logical order between them.

[0033] It should also be understood that, in the embodiments of the present invention, “plurality” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0034] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0035] In addition, the term "and / or" in the present invention is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects before and after are in an "or" relationship.

[0036] It should also be understood that the description of the various embodiments of the present invention focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced to each other, and for the sake of brevity, they will not be described one by one.

[0037] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0038] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0039] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0040] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0041] Figure 1 1 is a schematic diagram of a broadband oscillation full electromagnetic transient digital simulation detection system based on hardware-in-the-loop provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as Figure 1 As shown, the broadband oscillation full electromagnetic transient digital simulation detection system based on hardware in the loop includes:

[0042] Host computer, parallel computer, digital-analog simulation interface device and wide-band oscillation detection device, wherein:

[0043] The host computer is equipped with a digital model of the full electromagnetic transient state of the AC power grid with large-scale new energy access built with digital simulation software;

[0044] Parallel computers are used to realize the real-time simulation of digital-analog hybrid of digital models and actual physical control and protection devices in the loop to obtain simulation calculation results;

[0045] The digital-analog simulation interface device is used to realize hardware-in-the-loop. According to the analog quantity configuration of the branch concerned in the digital model and the signal table of the communication of the digital-analog simulation interface device, the simulation calculation result of the parallel computer is transmitted to the wide-band oscillation detection device according to the specified channel, and the action command of the wide-band oscillation detection device is received as the input quantity and returned to the digital model through the parallel computer. The digital model executes the preset control strategy according to the action command;

[0046] The wideband oscillation detection device is used to perform wideband oscillation detection on the digital model according to the simulation calculation result transmitted by the digital-analog simulation interface device, and determine the action command of the digital model according to the detection result and return it to the digital-analog simulation interface device.

[0047] Specifically, in view of the various broadband oscillation detection devices based on different principles that exist currently, the present invention provides a hardware-in-the-loop full electromagnetic transient digital simulation system, which utilizes the accuracy and real-time performance of the full electromagnetic transient simulation to realize the closed-loop simulation of the large-scale power grid electromagnetic transient digital model and the actual broadband oscillation detection physical control protection device, and conducts engineering application-level testing on the broadband oscillation detection device. The system has both physical and digital technical characteristics. It can not only give play to the characteristics of large scale and high accuracy of digital real-time simulation, but also fully reflect the characteristics of engineering applicability of physical simulation devices. It can conduct real-time simulation research on the entire process from electromagnetic transient to electromechanical transient, accurately simulate the broadband oscillation of the power grid, and then provide reliable guarantees for the network access detection and engineering application of the broadband oscillation detection device. The present invention is composed of a host computer, a parallel computer, a digital simulation interface device, and a broadband oscillation detection device.

[0048] Use digital simulation software on the host computer to build a full electromagnetic transient digital model of the AC power grid with large-scale new energy access. Build a full electromagnetic transient digital model of the AC large power grid according to actual needs. It can be consistent with the actual power grid architecture, or a simple power grid model can be built. Connect photovoltaic, double-fed wind turbines, direct-drive wind turbines and other new energy models to the branch according to the station or equivalent method.

[0049] According to the scale of AC power grid model construction, different levels of tests can be carried out on the device, such as engineering application level access test, and simple function test of the device. If the AC power grid and new energy are built according to the actual power grid, the generators, transformers, lines, and reactive equipment in the model are filled in according to the equipment parameters in the actual power grid. The refined model built in this way can test the device at the engineering application level.

[0050] Based on digital-analog simulation software, the powerful computing power of parallel computers is used to carry out 50 microseconds of real-time simulation calculations. This realizes the real-time digital-analog hybrid simulation of large-scale AC / DC power grid electromagnetic transient digital models and actual physical control and protection devices in the loop to improve the accuracy of the simulation model.

[0051] The function of the digital-analog simulation interface device is to realize hardware-in-the-loop. In the digital model, the analog quantity of the branch of concern is configured into a signal table that communicates with the interface device. The interface device sends the simulation calculation results of the parallel computer to the wide-band oscillation detection device according to the designated channel; at the same time, it receives the action command of the wide-band oscillation detection device and returns it to the digital model through the parallel computer as input to execute the established control strategy.

[0052] The broadband oscillation detection device is a broadband detection device that can be applied in actual power grid projects.

[0053] To ensure the real-time performance of digital simulation, each CPU core of a parallel computer cannot bear too many computing tasks. For large-scale AC power grids or when the scale of new energy access is large, it is usually necessary to decouple the primary main circuit and reasonably distribute the computing tasks to the parallel computer resources to ensure the real-time performance of the simulation. The decoupling principle is to perform electrical decoupling through decoupling elements, usually by selecting a longer AC line for decoupling. When the AC line is short, continuing to select the line for decoupling is likely to cause large calculation errors. At this time, the primary side of the transformer can be decoupled. When the digital model adds a control strategy that interacts with a wide-band oscillation detection device, the computing task of the communication interface is involved, and the secondary circuit can be signal decoupled if necessary.

[0054] For this system, the test method is provided as follows:

[0055] 1. Check the steady-state power flow of the AC power grid digital model, i.e., the bus voltage of key nodes, the current and power of key branches, etc. At the same time, check the real-time performance of the digital model running on a parallel computer. Electrically decouple the task blocks with large calculation tasks that affect the real-time performance of the model.

[0056] 2. Check the real-time operation of the digital model with an interface device. Because some CPU cores are assigned additional communication tasks, the computing tasks of individual CPU cores will increase, resulting in calculation timeout. It is necessary to further decouple the computing tasks of the CPU cores that have timed out, and continue to electrically decouple the computing task blocks. Alternatively, reallocate the CPU cores for the computing tasks.

[0057] 3. Check whether the voltage, current and power parameters of the monitoring branch are consistent with those in the digital simulation test model on the broadband oscillation detection device. If the data is inconsistent, adjust the analog ratio received by the broadband device first; if the analog ratio of the broadband device has a small adjustable range, you can also add a ratio to the analog quantity sent in the digital model.

[0058] 4. Provide three injection methods for fault characteristic frequency components

[0059] 1) By adjusting the parameters of the new energy model connected to the monitoring branch in the digital model, the system oscillation is caused. For example, the proportional parameters of the inner loop of the double-fed wind turbine side converter are adjusted. This method is more in line with the actual power system situation.

[0060] 2) In the monitoring branch of the digital model, a controllable current source is incorporated. Different frequencies and amplitudes are set in the controllable current source to inject harmonic current into the system. This method is ideal and suitable for simple amplitude comparison of several different fault characteristic frequencies.

[0061] 3) In the monitoring branch of the digital model, a controllable voltage source and its control loop are connected in series near the system side. The fault characteristic frequency and amplitude to be injected are set in the controllable voltage source, and the control loop is used to control the enabling of the controllable voltage source. This injection method can facilitate the widescreen device to trace the fault frequency.

[0062] 5. Functional test of broadband oscillator

[0063] 1) Monitoring function test of the device

[0064] That is, test the steady-state measurement function and fault characteristic frequency measurement function of the wide-screen oscillator. In steady state, whether the device can correctly display the voltage and current of the monitoring branch, and can correctly calculate the power and frequency. At the same time, test that the wide-band device should be able to correctly display all potential fault characteristic frequency components. Inject various fault characteristic frequency components into the monitoring branch of the digital model to check whether the device can normally monitor the disturbance fault frequency and amplitude.

[0065] 2) Device control strategy test

[0066] After the fault characteristic frequency component added to the monitoring branch of the digital model exceeds the action threshold set by the device, check whether the analog display of each branch of the device is correct. Put the general function pressure plate of the broadband oscillation detection device into operation to detect whether the broadband device is operating correctly: check whether the action message of the device is correct, and cut off the fault branch in the correct order according to the established control strategy; whether the output signal of the device is sent to the digital model through the interface device. After receiving the action signal sent by the device, the digital model cuts off the fault branch in the model. After that, in the digital model, the operating system runs stably without fault characteristic frequency components; the device measures normally without fault characteristic frequency components.

[0067] Therefore, the present invention provides a broadband oscillation full electromagnetic transient digital simulation detection system based on hardware-in-the-loop, which performs full electromagnetic transient digital simulation on the AC power grid with large-scale new energy access, and has the characteristics of large simulation scale and high accuracy. Then, through the hardware-in-the-loop method, real-time simulation (simulation step size of 50 microseconds) is performed with the broadband oscillation detection device, and various broadband detection devices can be accurately and reliably tested, providing reliable support for the application of the device in the actual power grid.

[0068] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A broadband oscillation full electromagnetic transient digital simulation detection system based on hardware in the loop, characterized in that: include: Host computer, parallel computer, digital-analog simulation interface device and wide-band oscillation detection device, wherein: The host computer is provided with a digital model of the full electromagnetic transient state of the AC power grid with large-scale new energy access built by digital simulation software; The parallel computer is used to realize the digital-analog hybrid real-time simulation of the digital model and the actual physical control protection device in the loop to obtain the simulation calculation result; The digital-analog simulation interface device is used to implement hardware-in-the-loop, and according to the analog quantity configuration of the branch concerned in the digital model and the signal table communicated by the digital-analog simulation interface device, the simulation calculation result of the parallel computer is transmitted to the wide-band oscillation detection device according to the specified channel, and the action command of the wide-band oscillation detection device is received as an input quantity and returned to the digital model through the parallel computer, and the digital model executes a preset control strategy according to the action command; The broadband oscillation detection device is used to perform broadband oscillation detection on the digital model according to the simulation calculation result transmitted by the digital-analog simulation interface device, and determine the action command of the digital model according to the detection result and return it to the digital-analog simulation interface device.

2. The system according to claim 1, characterized in that The digital model is a full electromagnetic transient digital model of a large AC power grid or a recommended power grid model built according to actual needs.

3. The system according to claim 1, characterized in that The electrical decoupling principle of the parallel computer is to perform electrical decoupling through a decoupling element, and to select a transformer primary side line that exceeds a preset length for decoupling.

4. The system according to claim 1, characterized in that The broadband oscillation detection of the broadband oscillation detection device includes: detecting the stable power flow of the digital model, and detecting the steady-state power flow of the digital model through the bus voltage of the key node and the current and power of the key branch.

5. The system according to claim 1, characterized in that The broadband oscillation detection of the broadband oscillation detection device further includes: detecting the real-time performance of the operation of the digital model.

6. The system according to claim 1, characterized in that The broadband oscillation detection of the broadband oscillation detection device also includes: monitoring whether the voltage, current, and power parameters of the branch are consistent with the voltage, current, and power parameters in the digital model; if the data are inconsistent, the analog quantity ratio received by the broadband device is adjusted preferentially; if the adjustable range of the analog quantity ratio of the broadband device is less than the preset value, the ratio is added to the analog quantity sent in the digital model.

7. The system according to claim 1, characterized in that The injection method of the fault characteristic frequency component of the digital model includes: By adjusting the parameters of the new energy model connected to the monitoring branch in the digital model, the system oscillation is caused; In the monitoring branch of the digital model, a controllable current source is incorporated, and different frequencies and amplitudes are set in the controllable current source to inject harmonic current into the system; In the monitoring branch of the digital model, on the system side, a controllable voltage source and its control loop are connected in series, and the fault characteristic frequency and amplitude to be injected are set in the controllable voltage source, and the control loop is used to control the enabling of the controllable voltage source.

8. The system according to claim 1, characterized in that The monitoring function test of the broadband oscillation detection device includes: Testing the steady-state measurement function and fault characteristic frequency measurement function of the widescreen oscillation monitoring device; Testing whether the widescreen oscillation monitoring device correctly displays all potential fault characteristic frequency components; Various fault characteristic frequency components are injected into the monitoring branch of the digital model to check whether the widescreen oscillation monitoring device can normally monitor the disturbance fault frequency and amplitude.

9. The system according to claim 1, characterized in that The control strategy test of the broadband oscillation detection device includes: After the fault characteristic frequency component added to the monitoring branch of the digital model exceeds the action threshold set by the device, check that the analog quantity display of each branch of the device is correct; The general function pressure plate of the broadband oscillation detection device is put into operation to detect whether the broadband oscillation detection device operates correctly and whether the action message is correct, and the faulty branch is cut off in the correct order according to the established control strategy; whether the export signal of the broadband oscillation monitoring device is sent to the digital model through the interface device; after the digital model receives the action signal sent by the device, the faulty branch in the digital model is cut off.

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