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

Method of detecting cascading failure in AC-DC hybrid system

A technology of AC/DC mixed connection and cascading failure, applied in the fault location, measurement power, measurement device and other directions, can solve the problems of cascading failure, commutation failure or even blocking, affecting the transmission capacity of the parallel operation AC channel, etc., and achieves a small amount of calculation. , to ensure the effect of orderly operation

Inactive Publication Date: 2015-06-17
SHANGHAI MUNICIPAL ELECTRIC POWER CO
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

AC / DC hybrid power grids will produce many new electrical characteristics during faults, which will adversely affect the action behavior of AC system relay protection
For example, the small transmission capacity of the DC line will affect the transmission capacity of the AC channel running in parallel; when multiple branch lines are fed into a receiving power grid at the same time, simultaneous commutation failures or even blockages are prone to occur; the voltage amplitude of the commutation bus drops and the If the zero-crossing point of the commutation line voltage moves forward, it can cause commutation failure in the DC transmission system, and in severe cases, it will lead to blocking
Therefore, the AC-DC hybrid power system is prone to cascading failures, which poses a great challenge to the safe operation of the power grid.

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
  • Method of detecting cascading failure in AC-DC hybrid system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0017] The present invention will be further described below in conjunction with accompanying drawing.

[0018] see figure 1 , the method for detecting the cascading failure of the AC / DC hybrid system of the present invention comprises the following steps:

[0019] Step S1, initializing the AC / DC hybrid system;

[0020] Step S2, simulating the disconnection or short circuit of a certain line in the AC / DC hybrid system, or simulating the instability of the generator, so as to set the fault;

[0021] Step S3, performing power flow calculation on the AC / DC hybrid system;

[0022] Step S4, judging whether the power flow is converged, if so, proceed to step S6; if not, proceed to step S5;

[0023] Step S5, increase or decrease partial load, and return to step S3;

[0024] Step S6, check the voltage of each DC commutation busbar in the AC-DC hybrid system, block the DC commutation busbars that are lower than the preset value, and proceed to the next step;

[0025] Step S7, judg...

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 method of detecting cascading failure in an AC-DC hybrid system. The method comprises steps: the AC-DC hybrid system is initialized; failure is set; load flow calculation is carried out; whether the load flow converges is judged, if yes, voltage of each DC commutation bus in the AC-DC hybrid system is checked, a DC commutation bus whose voltage is smaller than a preset value is locked, and the next step is carried out; if not, a part of loads are added or reduced, and load flow calculation is carried out again; whether a line is broken is judged, if yes, failure is set again; if not, loss load is calculated, the cascading event probability is obtained, and classification and confirmation on cascading failure in the AC-DC hybrid system are carried out. The method of the invention has the advantages that cascading failure can be effectively detected, and the amount of calculation is small.

Description

technical field [0001] The invention relates to a cascading failure of a power system, in particular to a method for detecting the cascading failure of an AC / DC hybrid system. Background technique [0002] In the AC-DC hybrid power system, there are interactions between AC and DC, DC and AC, and DC and DC. The AC / DC hybrid power grid will produce many new electrical characteristics during faults, which will have an adverse effect on the action behavior of the relay protection of the AC system. For example, the small transmission capacity of the DC line will affect the transmission capacity of the AC channel running in parallel; when multiple branch lines are fed into a receiving power grid at the same time, simultaneous commutation failures or even blockages are prone to occur; the voltage amplitude of the commutation bus drops and the If the zero-crossing point of the commutation line voltage moves forward, it can cause commutation failure in the DC transmission system, an...

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): G01R31/08G01R31/02
Inventor 何志伟秦虹杨素佳宗明黄维华
Owner SHANGHAI MUNICIPAL ELECTRIC POWER CO
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