Fast Fault Location Method for Converter in HVDC Transmission System

Abstract

The invention discloses a fast fault location method for an inverter of an HVDC transmission system, and the method is implemented through an HVDC transmission converter fault location system. The system comprises an original signal acquisition module, an additional signal acquisition module, a first type valve short circuit protection action judgment module, a converter differential protection action judgment module, a signal processing module, and a background management module. The method can achieve the warning of a fault condition of a first type valve short circuit protection under the condition that the additional equipment cost is greatly reduced, also can achieve the positioning of internal and external faults of a converter region which can enable the first type valve short circuit protection and the converter differential protection to be performed, can guarantee the fault location speed and accuracy, can guarantee the timely restart operation of the HVDC transmission system, and can further guarantee the power transmission and system stability.

Description

technical field [0001] The invention relates to a fault location method of a power system, in particular to a fast fault location method for a converter of a high-voltage direct current transmission system. Background technique [0002] The high-voltage direct current transmission system has large transmission capacity, long transmission distance and low transmission loss, so it occupies an increasingly important position in my country's power structure. The basic principle of HVDC transmission is: at the transmission end of the HVDC transmission system, a converter is used for rectification, and the three-phase AC power is converted into DC power. The inverter is used for inversion, and the direct current is converted into three-phase alternating current, and the electric energy is sent to the alternating current system at the power receiving end. [0003] The converter is one of the most important components in the HVDC transmission system, and undertakes the important co...

AI Technical Summary

Problems solved by technology

First, it is necessary to use the current information of a long time after the fault occurs, and the setting time of the first type of valve short-circuit protection is 0.5ms, and the protection and control function quickly causes the current information to change, so the existing fault location technology of the converter does not consider the fault The rapid action of the protection control after the occurrence causes the fault current information to mutate or even disappear, which is a practical problem, which leads to errors in fault location or even cannot be realized; The inverter fault location technology does not consider the impact of the fault outside the converter area on the protection action, so that the fault outside the converter area makes the relevant staff unable to correctly judge the fault location after the protection action. The above two problems may cause Relevant staff get the wrong fault location guidance information, which will delay the fault processing time

The third problem is that some existing technologies consider adding current measuring points to the 12-pulse bridge arms of the converter to detect the valve current of each bridge arm, so as to quickly locate the fault of the converter, but adding 12 measuring points , which greatly increases the cost of equipment and reduces the reliability of system operation

Images