Online monitoring method for short-circuit impedance of V/X connection traction transformer

Abstract

The invention discloses an online monitoring method for the short-circuit impedance of a V / X connection traction transformer. In two time intervals when the negative feeder line current of a power supply arm is 90-95% of the rated current and 95-100% of the rated current, the method tests and records a voltage vector and a current vector of the incoming line side and the feeder line side of the transformer respectively, calculates to obtain a primary test value of the short-circuit impedance by use of a deduced formula, and repeatedly tests and calculates for n times (n is not less than 20) to obtain two groups of primary test data; for each group of data, the method judges the relative standard deviation of the primary test data to eliminate the data with large error; and if the number of the eliminated data is less than n / 4, the average of the remaining data is the value of the tested short-circuit impedance. The method is simple to test and has high accuracy; and the curve of the monitored short-circuit impedance changing with time can be used as the basis for monitoring and judging the winding deformation.

Description

technical field [0001] The invention relates to an on-line monitoring technology of high-voltage electrical equipment of an electrified railway, in particular to an on-line monitoring technology of a V / X wiring traction transformer short-circuit reactance, and belongs to the technical field of electric equipment state detection. Background technique [0002] China's railway construction has ushered in unprecedented development. The large-scale construction of high-speed passenger dedicated lines has exceeded 7,000 kilometers in total. The operating speed has exceeded 350km / h. On February 19, 2010, the single-day passenger flow of national railways hit a record high, reaching 6.33 million passengers; Breaking through the annual transportation volume of 400 million tons; the great development of high-speed and heavy-haul railways is of great significance to promoting my country's economic and social development. It can be seen that the possible negative impact caused by the int...

AI Technical Summary

Problems solved by technology

Like other types of traction transformers, the winding deformation test is an important test content. The methods mainly include low-voltage pulse method, frequency oscillation method and short-circuit reactance method. Due to the particularity of the winding connection mode of the V / X connection transformer, the The on-line monitoring method of other transformer winding deformation is not applicable to it, so the current detection methods are all off-line testing methods

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