The present disclosure provides a grid forming vector current control system configured to emulate a virtual synchronous machine (VSM). The disclosed system comprises a droop control unit, a current control unit, a virtual admittance unit and a phase locked loop (PLL) unit. The virtual admittance unit and the PLL unit are configured to emulate an inertia of the VSM. A virtual current source is connected in parallel to the VSM.

Grid forming vector current control

The invention discloses an MMC frequency coupling impedance modeling method under model prediction AC voltage control. An MMC under AC voltage control is predicted by using a model to serve as a modeling object; through circuit equation frequency domain small signal modeling and model prediction AC voltage control loop frequency domain small signal modeling, an MMC small signal impedance model isobtained through derivation, and the model is composed of MMC positive sequence impedance, MMC negative sequence impedance and positive sequence impedance and negative sequence impedance frequency coupling terms caused by MMC internal complex harmonic dynamic characteristics. The accuracy of the small signal impedance model established by the method is verified by simulation, and the method and the basis can be provided for MMC small signal impedance modeling and stability analysis based on an MMC system.

MMC frequency coupling impedance modeling method under model prediction AC voltage control

The invention relates to a method and system for determining an interaction link influencing the stability in a direct-driven wind power system, belongs to the technical field of wind power generation, and solves the problems of poor pertinence and limitation of an existing analysis method. The method comprises the following steps: constructing an interaction energy function corresponding to eachinteraction link between subsystems in each subsystem group based on an interconnection model; performing measuring to obtain a state variable change track corresponding to each subsystem in each subsystem group in the oscillation process of the direct-driven wind power system; determining an interaction energy change track corresponding to each interaction link in combination with a correspondinginteraction energy function so as to obtain an interaction energy change track of the subsystem group; and analyzing the influence of the interaction link included in each subsystem group on the stability of the direct-driven wind power system according to the interaction energy change track so as to determine the interaction link for inducing the oscillation of the direct-driven wind power system. According to the method, the influence degree of different interaction links in the direct-driven wind power system on the stability can be obtained, the pertinence is high, and the accuracy is high.

Method and system for determining interaction link influencing stability in direct-driven wind power system

The invention discloses a doubly-fed fan grid-connected port output impedance modeling and stability analysis method. The method is characterized in that influence of a doubly-fed fan stator flux linkage component and phase-locked loop and current loop links in a fan control system on output impedance of a system is comprehensively considered, a doubly-fed fan grid-connected port overall output impedance model and a weak power grid impedance model are established, based on the two models and a generalized Nyquist stability criterion, influence of grid-connected doubly-fed fan output impedancecharacteristics on stability under the weak power grid condition is analyzed, and then optimization design of fan control system loop parameters is guided. The impedance model provided by the invention is simple in structure and has good accuracy; the stability analysis method is simple and effective, and the model and the method are provided for doubly-fed fan grid-connected small-interference stability analysis under the weak power grid condition.

Doubly-fed fan grid-connected port output impedance modeling and stability analysis method

The invention discloses a virtual synchronous control method for a double-fed fan with a low voltage ride through function. The method is characterized in that the original power and current double closed-loop vector control structure of the fan converter is not changed, and inertia support of grid-connected point frequency and voltage can be realized only by constructing a virtual synchronous control loop. The process is as follows: when the power grid frequency fluctuates or the voltage amplitude drops slightly, the virtual synchronous control loop calculates according to a set droop coefficient to obtain a power compensation instruction, and sets inertia response time through the damping controller and then compensates the power compensation instruction to an original power instructionof the converter. Meanwhile, when the voltage of the grid-connected point drops deeply, the response rate of reactive compensation under the working condition of the fault power grid is improved by automatically adjusting the damping coefficient of the damping controller, and the requirement of the grid-connected standard for the low-voltage ride-through capability of the fan is met.

Virtual synchronous control method for double-fed fan with low-voltage ride through function

The invention discloses a multi-energy complementary power supply system for an offshore oil drilling platform and a control method thereof. According to the method, the load power fluctuation is divided into three parts through virtual impedance, namely a rapid dynamic part, a intermediate frequency transition part, and a low frequency dynamic part, wherein the power of the rapid dynamic part isregulated by power-type energy storage equipment, the power of the intermediate frequency transition part is regulated by energy-type energy storage equipment, the power of the low frequency dynamic part is regulated by a gas turbine, and the gas turbine provides the power support during the steady state at the same time. According to the control method, the gas turbine is added into the energy storage management and is used for managing the steady state part in the load power fluctuation while the advantages of the energy-type energy storage equipment and the power-type energy storage equipment are fully exerted, the charging and discharging times of a storage battery and the required capacity of the battery are effectively reduced; when a distributed power generation system fails or cannot work by the natural environment constraint, the gas turbine with the leading function increases the output power at the moment, the problem that in a traditional method, due to the fact that the energy-type energy storage equipment works for a long time, the state of charge is lower than a lower limit value, then partial load can only be cut off is solved, and the system reliability is improved.

Multi-energy complementary power supply system for offshore oil drilling platform and control method thereof

Popular Tasks used by Researchers

How can I help with your research?

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

We encountered an error while loading the panel. Please try refreshing the page.

Something went wrong

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

Anyone with the link can view this chat. You can switch it back to private anytime.

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Wang Shinan

Author Tools

Chat about Author

Papers

Doubly-fed fan grid-connected port output impedance modeling and stability analysis method

Virtual synchronous control method for double-fed fan with low-voltage ride through function

Multi-energy complementary power supply system for offshore oil drilling platform and control method thereof