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

A technology of constant AC voltage and model prediction, applied in AC network circuits, power transmission AC networks, circuit devices, etc., can solve the problems of no MMC impedance modeling, inaccurate MMC impedance models, etc.

Active Publication Date: 2020-08-14
ZHEJIANG UNIV +1
View PDF6 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Existing studies on the establishment of the impedance model of the MMC converter station are not yet complete. The current mainstream modeling ideas only establish the MMC positive sequence impedance and negative sequence impedance models under the traditional constant AC voltage control, and consider the positive sequence impedance, negative sequence impedance The sequence impedances are decoupled from each other; in fact, due to the internal harmonic dynamic process of MMC, there is a frequency coupling effect between positive and negative sequence impedances, so the established MMC impedance model is not accurate
In addition, the current mainstream modeling ideas do not carry out impedance modeling for the MMC under the control of the model-based predetermined AC voltage, and cannot analyze the instability and resonance problems faced by the MMC system under the control of the model-based predetermined AC voltage.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • MMC frequency coupling impedance modeling method under model prediction AC voltage control
  • MMC frequency coupling impedance modeling method under model prediction AC voltage control
  • MMC frequency coupling impedance modeling method under model prediction AC voltage control

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0071] In order to describe the present invention more specifically, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0072] like figure 1 shown, v ga , v gb , v gc respectively represent the three-phase output voltage of the converter, i ga , i gb , i gc respectively represent the three-phase output current of the converter, i ua , i ub , i uc Indicates the three-phase upper arm current, i la , i lb , i lc Indicates the three-phase lower arm current, V dc represents the DC bus voltage, i dc Indicates the DC bus current. It can be seen that the MMC consists of 3-phase 6 bridge arms, each bridge arm is composed of a number of N sub-modules and a bridge arm inductor L in series, the MMC output voltage control can be adjusted by adjusting the sub-modules of each bridge arm in the operating state Quantity achieved. Since the sub-module contains an energy storage...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

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.

Description

technical field [0001] The invention belongs to the technical field of power electronic equipment modeling, in particular to a method for modeling frequency coupling impedance of an MMC (modular multilevel converter) under the control of a model pre-determined alternating voltage. Background technique [0002] High-voltage flexible direct current transmission (HVDC) based on MMC has a series of advantages such as low output harmonic content, low switching loss, no need for reactive power compensation, black start capability, and high modularity. It is the preferred solution for large-scale and long-distance power transmission. ; Typical projects that have been put into operation include the Borwin3 flexible DC transmission project in Germany and the four-terminal flexible DC transmission project in Zhangbei, China, which have produced huge economic and environmental benefits. [0003] The basic structure of MMC is as follows figure 1 As shown, it mainly includes 3-phase 6 b...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): H02J3/36
CPCH02J3/36H02J2203/20Y02E60/60
Inventor 年珩朱茂玮邹常跃赵晓斌许树楷冯俊杰
Owner ZHEJIANG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap