Hardware-in-the-loop broadband oscillation full electromagnetic transient simulation detection system

Abstract

The application discloses a wide-frequency oscillation full electromagnetic transient numerical simulation detection system based on a hardware-in-the-loop, which comprises: a host computer provided with a digital model of full electromagnetic transient of an alternating current power grid with large-scale new energy access built by numerical simulation software; a parallel computer is used to realize numerical simulation hybrid real-time simulation of the digital model and an actual physical control protection device in the loop to obtain simulation calculation results; a numerical simulation interface device is used to configure analog signals of a branch of interest in the digital model and a signal table communicated by the numerical simulation interface device, transmit the simulation calculation results of the parallel computer to a wide-frequency oscillation detection device according to a specified channel, and receive an action command of the wide-frequency oscillation detection device as an input quantity and return the input quantity to the digital model through the parallel computer, so that the digital model executes a preset control strategy according to the action command; and the wide-frequency oscillation detection device is used to detect the digital model for wide-frequency oscillation according to the simulation calculation results transmitted by the numerical simulation interface device.

Description

Technical Field

[0001] This invention relates to the field of safe and stable operation technology of large-scale AC power grids with access to new energy sources and new power electronic equipment, and more specifically, to a hardware-in-the-loop broadband oscillation full electromagnetic transient simulation detection system. Background Technology

[0002] To meet the demands of energy transition and environmental protection, renewable and clean energy, as well as power electronic equipment, are increasingly prevalent in AC power grids. This has led to frequent subsynchronous and supersynchronous oscillations, severely impacting the safe and stable operation of power systems. Different types of disturbances, such as harmonics, interharmonics, and oscillations, have different causes and require different suppression methods. To address broadband oscillations in new power systems,

[0003] Domestic and foreign researchers have proposed many methods for detecting broadband oscillation signals, including discrete Fourier transform, Planck parameter estimation, wavelet analysis, and Hilbert-Huang transform. Many broadband oscillation detection devices have been developed for the detection and identification of disturbance frequencies.

[0004] To ensure the successful application of these technologies and devices in actual power grids, it is essential to conduct safety, accuracy, and reliability tests on these broadband oscillation detection devices based on different principles. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a hardware-in-the-loop wideband oscillation full electromagnetic transient numerical simulation detection system.

[0006] According to one aspect of the present invention, a hardware-in-the-loop broadband oscillation full electromagnetic transient digital simulation detection system 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 entire electromagnetic transient state of an AC power grid with large-scale new energy access, built using simulation software.

[0008] Parallel computers are used to perform real-time hybrid simulation of digital models and actual physical control and protection devices in the loop, and to obtain simulation results.

[0009] The analog-to-digital simulation interface device is used to implement hardware-in-the-loop. Based on the analog quantity configuration of the branches of interest in the digital model and the signal table for communication between the analog-to-digital simulation interface device and the parallel computer, the simulation calculation results are transmitted to the broadband oscillation detection device through the specified channel. The action commands of the broadband oscillation detection device are received as input quantities and returned to the digital model through the parallel computer. The digital model executes the preset control strategy according to the action commands.

[0010] The broadband oscillation detection device is used to perform broadband oscillation detection on the digital model based on the simulation calculation results transmitted by the digital simulation interface device, and to determine the action commands of the digital model based on the detection results and return them to the digital simulation interface device.

[0011] Optionally, the digital model is a fully electromagnetic transient digital model of an AC power grid or a proposed power grid model built according to actual needs.

[0012] Optionally, the electrical decoupling principle of the parallel computer is to decouple the circuit through decoupling elements, selecting the primary side line of the transformer that exceeds the preset length for decoupling.

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

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

[0015] Optionally, the broadband oscillation detection of the broadband oscillation detection device also includes: monitoring whether the voltage, current, and power parameters of the monitoring 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 first. If the adjustable range of the analog quantity ratio of the broadband device is less than the preset value, a ratio is added to the transmitted analog quantity in the digital model.

[0016] Optionally, the injection methods for the fault characteristic frequency components of the digital model include:

[0017] By adjusting the parameters of the new energy model connected to the monitoring branch in the digital model, system oscillations are induced.

[0018] In the monitoring branch of the digital model, a controllable current source is connected in parallel, 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, a controllable voltage source and its control loop are connected in series on 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 enable 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 wide-screen oscillation monitoring device;

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

[0023] Various fault characteristic frequency components were injected into the monitoring branch of the digital model to check whether the wide-screen oscillation monitoring device could normally monitor the frequency and amplitude of disturbance faults.

[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 that the analog quantity display of each branch of the device is correct.

[0026] The main function board of the broadband oscillation detection device is activated to check whether the broadband oscillation detection device operates correctly and whether the action message is correct. According to the established control strategy, the faulty branch is disconnected in the correct sequence. The output signal of the broadband oscillation monitoring device is sent to the digital model through the interface device. After receiving the action signal sent by the device, the digital model disconnects the faulty branch in the digital model.

[0027] Therefore, this invention provides a hardware-in-the-loop broadband oscillation full electromagnetic transient digital simulation detection system, which performs full electromagnetic transient digital simulation on AC power grids with large-scale new energy access. It features large simulation scale and high accuracy. Furthermore, it performs real-time simulation with a broadband oscillation detection device through hardware-in-the-loop (simulation step size of 50 microseconds), which can accurately and reliably test various broadband detection devices and provide reliable support for the application of the devices in actual power grids. Attached Figure Description

[0028] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0029] Figure 1 This is a schematic diagram of a hardware-in-the-loop broadband oscillation full electromagnetic transient numerical simulation detection system provided by an exemplary embodiment of the present invention. Detailed Implementation

[0030] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is obvious that the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein.

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

[0032] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0033] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[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 defined or given contrary instructions in the context.

[0035] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0036] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0037] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

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

[0039] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

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

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

[0042] The host computer, parallel computer, digital-to-analog interface device, and wideband oscillation detection device are included.

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

[0044] Parallel computers are used to perform real-time hybrid simulation of digital models and actual physical control and protection devices in the loop, and to obtain simulation results.

[0045] The analog-to-digital simulation interface device is used to implement hardware-in-the-loop. Based on the analog quantity configuration of the branches of interest in the digital model and the signal table for communication between the analog-to-digital simulation interface device and the parallel computer, the simulation calculation results are transmitted to the broadband oscillation detection device through the specified channel. The action commands of the broadband oscillation detection device are received as input quantities and returned to the digital model through the parallel computer. The digital model executes the preset control strategy according to the action commands.

[0046] The broadband oscillation detection device is used to perform broadband oscillation detection on the digital model based on the simulation calculation results transmitted by the digital simulation interface device, and to determine the action commands of the digital model based on the detection results and return them to the digital simulation interface device.

[0047] Specifically, addressing the diverse range of broadband oscillation detection devices based on different principles currently available, this invention presents a hardware-in-the-loop (HIL) all-electromagnetic transient digital simulation system. Leveraging the accuracy and real-time performance of HIL simulation, it achieves closed-loop simulation of large-scale power grid electromagnetic transient digital models and actual broadband oscillation detection physical control and protection devices, enabling engineering application-level testing of the broadband oscillation detection devices. This system combines the characteristics of both physical and digital technologies. It leverages the large scale and high accuracy of digital real-time simulation while fully reflecting the engineering applicability of physical simulation devices. It can conduct real-time simulation studies of the entire process from electromagnetic transients to electromechanical transients, accurately simulating broadband oscillations in the power grid, thus providing a reliable guarantee for the grid access testing and engineering application of broadband oscillation detection devices. This invention consists of a host computer, a parallel computer, a digital simulation interface device, and a broadband oscillation detection device.

[0048] A full electromagnetic transient digital model of an AC power grid with large-scale renewable energy integration is built on a host computer using digital simulation software. The full electromagnetic transient digital model of the large AC power grid can be built according to actual needs, either matching the actual power grid architecture or using a simplified model. Renewable energy models such as photovoltaic, doubly-fed induction generator (DFIG), and direct-drive wind turbines are integrated into the branches according to the method of power plant or equivalent.

[0049] Depending on the scale of the AC power grid model, different levels of testing can be conducted on the device, such as grid connection testing at the engineering application level, or simple functional testing of the device. If both the AC power grid and the new energy source are built according to the actual power grid, and the generators, transformers, lines, and reactive power equipment in the model are filled in according to the equipment parameters in the actual power grid, then the refined model built in this way can be used for engineering application-level testing of the device.

[0050] Based on numerical simulation software, and leveraging the powerful computing capabilities of parallel computers, real-time simulation calculations of 50 microseconds are performed. This enables real-time hybrid numerical-analog simulation of large-scale AC / DC power grid electromagnetic transient digital models and actual physical control and protection devices in the loop, thereby improving the accuracy of the simulation model.

[0051] The function of the analog-to-analog simulation interface device is to realize hardware-in-the-loop. In the digital model, the analog quantities of the branches of interest are configured with signal tables that communicate with the interface device. The interface device sends the simulation calculation results of the parallel computer to the broadband oscillation detection device through the specified channels. At the same time, it receives the action commands of the broadband oscillation detection device, and returns them to the digital model as input quantities through the parallel computer to execute the predetermined control strategy.

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

[0053] To ensure the real-time performance of digital simulations, each CPU core of a parallel computer cannot handle excessive computational tasks. For large-scale AC power grids or when a large amount of new energy is integrated, it is usually necessary to decouple the primary circuit and allocate computational tasks reasonably among parallel computer resources to ensure the real-time performance of the simulation. The decoupling principle is to achieve electrical decoupling through decoupling components, typically using a longer AC line. When the AC line is short, continuing to select a line for decoupling can easily lead to large computational errors; in this case, the primary side of the transformer can be decoupled. When the digital model incorporates control strategies that interact with a broadband oscillation detection device, the computational workload involving the communication interface increases, and signal decoupling of the secondary circuit may be necessary.

[0054] The testing methods for this system are as follows:

[0055] 1. Examine the steady-state power flow of the AC power grid digital model, i.e., the bus voltage of key nodes, and the current and power of key branches. Simultaneously, check the real-time performance of the digital model running on a parallel computer. Electrically decouple task blocks with large computational demands that affect the model's real-time performance.

[0056] 2. With interface devices, check the real-time performance of the digital model. Because some CPU cores are additionally allocated communication tasks, the computational workload on individual CPU cores increases, leading to timeouts. Further decoupling of the computational tasks on the timed-out CPU cores is needed, including further electrical decoupling of the computational task blocks. Alternatively, the computational tasks can be reassigned to different CPU cores.

[0057] 3. Check whether the voltage, current, and power parameters of the monitored branch on the broadband oscillation detection device are consistent with those in the digital simulation test model. If inconsistencies are found, prioritize adjusting the analog input ratio received by the broadband device; if the adjustable range of the analog input ratio of the broadband device is small, a ratio can also be added to the transmitted analog input in the digital model.

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

[0059] 1) Inducing system oscillations by adjusting the parameters of the new energy model connected to the monitoring branch in the digital model. For example, adjusting the inner loop proportional parameters of the converter on the doubly-fed induction generator (DFIG) side. This method is more consistent with the actual power system situation.

[0060] 2) Integrate a controllable current source into the monitoring branch of the digital model. Set different frequencies and amplitudes in the controllable current source to inject harmonic current into the system. This method is relatively ideal and suitable for comparing the amplitudes of several simple 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 enable of the controllable voltage source. This injection method facilitates fault frequency tracing in widescreen devices.

[0062] 5. Functional testing of the wideband oscillation device

[0063] 1) Testing the monitoring function of the device

[0064] This involves testing the steady-state measurement function and fault characteristic frequency measurement function of the wide-screen oscillation device. In steady state, the device should correctly display the voltage and current of the monitored branch and accurately calculate the power and frequency. Simultaneously, the wide-screen device should be able to correctly display all potential fault characteristic frequency components. Various fault characteristic frequency components should be injected into the monitoring branch of the digital model to check whether the device can normally monitor the frequency and amplitude of disturbance faults.

[0065] 2) Control strategy test of the device

[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 that the analog display of each branch of the device is correct. Activate the main function switch of the broadband oscillation detection device and check whether the broadband device operates correctly: check whether the device's action message is correct, whether the faulty branch is disconnected in the correct sequence according to the established control strategy; and whether the device's output signal is sent to the digital model through the interface device. After receiving the action signal from the device, the digital model disconnects the faulty branch in the model. Afterwards, the operating system in the digital model operates stably with no fault characteristic frequency component; the device measurements are normal with no fault characteristic frequency component.

[0067] Therefore, this invention provides a hardware-in-the-loop broadband oscillation full electromagnetic transient digital simulation detection system, which performs full electromagnetic transient digital simulation on AC power grids with large-scale new energy access. It features large simulation scale and high accuracy. Furthermore, it performs real-time simulation with a broadband oscillation detection device through hardware-in-the-loop (simulation step size of 50 microseconds), which can accurately and reliably test various broadband detection devices and provide reliable support for the application of the devices in actual power grids.

[0068] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A hardware-in-the-loop wide frequency oscillation full electromagnetic transient numerical simulation detection system, characterized in that, The method comprises the following steps: The host computer, parallel computer, digital-analog simulation interface device and wide frequency oscillation detection device are used, The host computer is provided with a digital model of full electromagnetic transient of AC power grid with large-scale new energy access built by digital-analog 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 a loop to obtain simulation calculation results; The digital-analog simulation interface device is used to realize hardware-in-the-loop, configure analog quantities of a branch of interest in the digital model and a signal table communicated by the digital-analog simulation interface device, transmit the simulation calculation results of the parallel computer to the wide frequency oscillation detection device according to a specified channel, and return the action command of the wide frequency oscillation detection device to the digital model as an input quantity through the parallel computer, so that the digital model executes a preset control strategy according to the action command; The wide frequency oscillation detection device is used to detect the wide frequency oscillation of the digital model according to the simulation calculation results transmitted by the digital-analog simulation interface device, and determine the action command of the digital model according to the detection results and return the action command to the digital-analog simulation interface device.

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

3. The system of claim 1, wherein, The electrical decoupling principle of the parallel computer is to perform electrical decoupling through a decoupling element, and a transformer primary side line exceeding a preset length is selected for decoupling.

4. The system of claim 1, wherein, The wide frequency oscillation detection of the wide frequency 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 a key node and the current and power of a key branch.

5. The system of claim 1, wherein, The wide frequency oscillation detection of the wide frequency oscillation detection device further includes detecting the real-time performance of the digital model.

6. The system of claim 1, wherein, The wide frequency oscillation detection of the wide frequency oscillation detection device further includes monitoring whether the voltage, current and power parameters of a branch are consistent with the voltage, current and power parameters in the digital model, and if the data are inconsistent, preferentially adjusting the analog quantity variable ratio received by the wide frequency device; if the adjustable range of the analog quantity variable ratio of the wide frequency device is less than a preset value, adding a variable ratio to the transmitted analog quantity in the digital model.

7. The system of claim 1, wherein, The injection mode of the fault characteristic frequency component of the digital model includes: Adjusting the parameters of a new energy model accessed by a monitoring branch in the digital model to cause system oscillation; 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, and harmonic currents are injected into the system; In the monitoring branch of the digital model, a controllable voltage source and its control loop are connected in series on the system side, and the fault characteristic frequency to be injected and its amplitude are set in the controllable voltage source, and the control loop is used to control the enablement of the controllable voltage source.

8. The system of claim 1, wherein, The monitoring function test of the wide frequency oscillation detection device includes: Testing the steady-state measurement function and the fault characteristic frequency measurement function of the wide frequency oscillation detection device; Testing whether the wide frequency oscillation detection device correctly displays all potential fault characteristic frequency components; Inject various fault characteristic frequency components on the monitoring branch of the digital model, and check whether the wide-frequency oscillation monitoring device can normally monitor the disturbance fault frequency and amplitude.

9. The system of claim 1, wherein, The control strategy test of the wide-frequency oscillation detection device includes: After the fault characteristic frequency components added on the monitoring branch of the digital model exceed the action threshold set by the device, check whether the analog quantity displayed by each branch of the device is correct; Put the total function press plate of the wide-frequency oscillation detection device, detect whether the wide-frequency oscillation detection device correctly acts and whether the action message is correct, cut off the fault branch in the correct order according to the established control strategy; check whether the outlet signal of the wide-frequency oscillation monitoring 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 digital model.

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