Flexible DC transmission dynamic stability determining and controlling method

A flexible DC power transmission and dynamic stability technology, applied in the direction of AC power input conversion to DC power output, AC network circuit, AC power input conversion to AC power output, etc. Conducive to engineering practice, the method is simple and easy to implement

Active Publication Date: 2019-04-19
SICHUAN UNIV
View PDF5 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] 2) Through the impedance modeling of the system, whether the input impedance characteristic of the system is negative is used to judge whether the system is stable. First, the overall modeling is required; : Wu Wenhua, Chen Yandong, Luo An, Zhou Leming, Zhou Xiaoping, Yang Ling, Huang Xucheng. DC Impedance

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
  • Flexible DC transmission dynamic stability determining and controlling method
  • Flexible DC transmission dynamic stability determining and controlling method
  • Flexible DC transmission dynamic stability determining and controlling method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. A method for judging the dynamic stability of flexible direct current transmission in the present invention comprises the following steps:

[0030] Step 1: Unlock the converter station of the HVDC system, so that the HVDC system operates in a non-islanding control mode; Step 2: Extract the corresponding parameters of the HVDC system, the parameters include the effective value of the AC system voltage U t0 , flexible DC output reactive power Q vsc0 , the gain k of the phase-locked loop PLL p and the proportional-integral time constant k of the phase-locked loop PLL i ;Step 3: Taking the rated capacity of the converter station and the AC system voltage as the reference value, calculate the short-circuit ratio SCR, and calculate U t0 , Q vsc0 The per unit value of ; Step 4: Calculate the key stable component where ω is the angular fr...

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 a flexible DC transmission dynamic stability determining and controlling method which comprises the steps of: unlocking a converter station of a flexible DC transmission system, and allowing the flexible DC transmission system to operate in a non-island control mode; extracting corresponding parameters of the flexible DC transmission system, wherein the parameters include an AC system voltage effective value Ut0, a flexible DC external reactive power Qvsc0, a gain kp of a phase locked loop PLL, and a proportional integral time constant ki of the phase locked loop PLL; calculating a short-circuit ratio SCR, the per-unit value of Ut0 and Qvsc0; calculating a key stable component; and checking the sign of the key stable component and determining the stability of the flexible DC transmission system. The method of the invention only needs to simply calculate the value of the key stable component, determines the stability of the system by the sign of the value, is simple and easy, and is beneficial to engineering practice.

Description

technical field [0001] The invention relates to the technical field of flexible direct current transmission system control, in particular to a method for judging and controlling the dynamic stability of flexible direct current transmission. Background technique [0002] Compared with traditional LCC-HVDC, flexible direct current transmission VSC-HVDC can provide reactive power support for AC system without commutation failure, so it has wider application prospects in weak connection scenarios. In particular, in the island control mode (constant AC voltage, constant AC frequency), it can realize new functions that conventional transmission methods do not have, such as flexible grid connection of new energy, power transmission to passive systems, and auxiliary grid black start. [0003] When the VSC-HVDC is connected in parallel with the AC system, the system frequency is determined by the AC main network. At this time, the VSC must adopt the non-islanding control mode, but it...

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
IPC IPC(8): H02J3/36
CPCH02J3/36Y02E60/60H02M5/4585H02J2003/365H02M7/7575
Inventor 李保宏刘天琪陶艳
Owner SICHUAN 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