Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Determination method of high voltage direct current converter commutation overlap angle

A high-voltage DC, determination method technology, applied in the direction of DC network circuit devices, DC circuits can reduce harmonics/ripples, electrical components, etc., and can solve the problem of reducing the accuracy of harmonic current calculations, and the inconsistency of commutation and non-commutation durations. Re-identity, filter safety issues, etc.

Inactive Publication Date: 2010-09-15
ZHEJIANG UNIV
View PDF2 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to non-ideal factors in the actual system, such as negative sequence fundamental voltage, background harmonic voltage, asymmetry of the interval between the firing angle (turn-off angle) of the converter, the deviation of the converter transformer impedance, and the deviation of the converter ratio, each valve The commutation and non-commutation durations will no longer be the same, and the traditional method based on ideal conditions obviously cannot take into account the interaction of the above factors, which will lead to a reduction in the accuracy of harmonic current calculations, and may cause filtering under certain harsh conditions. server configuration security issue

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
  • Determination method of high voltage direct current converter commutation overlap angle
  • Determination method of high voltage direct current converter commutation overlap angle
  • Determination method of high voltage direct current converter commutation overlap angle

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] In this example, the test working condition is unipolar single valve group (12 pulsation) metal circuit wiring method, such as Figure 8 As shown, the transmission power is 1250MW, the load level is 100%, and the DC current is the rated value of 3.125kA. The method for determining the commutation overlap angle is as follows:

[0057] (1) According to the sequence of triggering moments of the six thyristors in the six-pulse rectifier bridge circuit, a working cycle of the six-pulse rectifier bridge circuit is divided into 6 commutation segments and 6 corresponding non-commutation segments, and each The commutation method of the commutation section;

[0058] The YY bridge and the YD bridge can be equivalently decoupled into a six-pulse full-wave rectifier unit through conversion ratio conversion and star-delta transformation. Since the YY bridge and the YD bridge have similarities in circuit structure, the equivalent circuit after decoupling is the same ,like figure 2 ...

Embodiment 2

[0118] The test load level of this embodiment is 10% of the rated power, the DC current is 0.3125kA, and other conditions are consistent with those described in Embodiment 1, then the following results can be obtained according to the steps of Embodiment 1:

[0119] Table 7 Commutation overlap angle results (10% load level)

[0120]

[0121]

[0122] As can be seen from Table 7, the maximum relative deviation between the method of the present invention and the simulation result of PSCAD / EMTDC under the low load level is 0.654%, and the maximum absolute deviation is 0.023°, which still has very high precision; if the result calculated by the traditional method is μ =3.642°, the maximum absolute deviation from PSCAD / EMTDC is 0.403°, and the relative deviation is close to 10%, which is already larger than the firing angle deviation (±0.2°).

[0123] Generally, it can be seen from the above comparison that the traditional method to calculate the commutation overlap angle can...

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 determination method of a high voltage direct current converter commutation overlap angle, aiming to solve the problem that a traditional method for calculating a commutation overlap angle can not take nonideal factors including background harmonics into consider to cause poor design performance of a wave filter. The method comprises the following steps of dividing the working period of a converter into six commutation sections and six non-commutation sections; establishing a differential equation to each commutation section by considering factors such as background harmonic interference, asymmetric fundamental voltage, asymmetric converter trigger angle distances, commutation impedance deviation and the like; and accurately calculating the commutation overlap angle. The invention efficiently enhances the calculation efficiency when ensuring the accuracy and can enhance the design quality of an alternating current converter.

Description

technical field [0001] The invention relates to the technical field of high voltage direct current transmission engineering, in particular to a method for determining the commutation overlap angle of a high voltage direct current converter. Background technique [0002] The structure of the rectifier station of the traditional two-terminal HVDC transmission system is shown as follows: figure 1 As shown, the transformer connected through YY and YD steps down the AC power on the AC busbar of the converter station (referred to as the grid side or AC side) into a lower voltage valve side AC power, and at the same time commutates the voltage for the upper and lower bridges Provide a phase difference of 30 degrees, and the converter containing the rectification circuit inside converts the three-phase AC power after step-down into DC side DC power, and the harmonics are filtered out by the smoothing reactance and DC filter system, and then passed through the high-voltage DC line D...

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): H02J1/00H02J1/02
Inventor 徐政薛英林李普明王峰屠卿瑞
Owner ZHEJIANG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com